Functionalized 1,3-Thiazolidin-4-Ones from 2-Oxo-Acenaphthoquinylidene- and [2.2]Paracyclophanylidene-Thiosemicarbazones

The reactions of dialkyl acetylenedicarboxylates with various 2-oxo-acenaphthoquinylidene- and 4-acetyl[2.2]paracyclophanylidene-thiosemicarbazones were investigated. Using simple experimental procedures, 1,3-Thiazolidin-4-ones derived from acenaphthequinone or [2.2]paracyclophane were obtained as major products in good yields. In the case of allyl derivative of acenaphthoquinylidene-thiosemicarbazones, a complex structure of tetramethyl 5-(2-(((Z,E)-N-allyl-N′-(2-oxoacenaphthylen-1(2H)-ylidene)carbamohydrazonoyl)thio)-1,2,3-tris-(methoxycarbonyl)-cyclopropyl)-4-methoxy-7-oxabicyclo[2.2.1]hepta-2,5-diene-1,2,3,6-tetracarboxylate was formed. Single crystal X-ray analysis was used as an efficient tool to confirm the structure of the synthesized compounds as well as different spectroscopic data (1H-NMR, 13C-NMR, 2D-NMR, mass spectrometry and elemental analysis). The mechanism of the obtained products was discussed.


Reaction of Compounds 5a-e with Dimethyl Acetylenedicarboxylate (DMAD, 6)
A mixture of dimethyl acetylenedicarboxylate (DMAD, 6a) and (Z)-N-unsubstituted/ substituted-2-(2-oxoacenaphthylen-1-(2H)-ylidene)thiosemicarbazones 5a-e, was refluxed in absolute EtOH for 20-30 min. The reaction revealed the complete disappearance of compounds 5a-e and 6a to give compounds 7a-e in 70-76% yields (Scheme 3). Surprisingly, only in the case of allyl derivative 5d, an unexpected compound 8d was obtained in 10% yield (Scheme 3). Different spectroscopic data were insufficient to determine completely the correct structure of this compound. Different nucleophilic sites on thiosemicarbazone derivatives 5a-e were expected to participate in the reaction and formation of the product. Nucleophilic attack of lone pair of electrons of the sulfur atom in the thione group in 5a-e to the acetylenic carbon in 6a would give the Zwitter ions 9a-e. Neutralization of 9a-e would give the intermediate 10a-e. Subsequently another nucleophilic attack from a lone pair of electrons of 2 NH or 4 NH on CO2Me; would yield the corresponding 4thiazolidinones 7a-e and/or 12a-e via the loss of methanol (Scheme 4). The 1 H and 13 C-NMR spectral data (see details in Supplementary Materials) were used as an important tool for excluding some

Reaction of Compounds 5a-e with Dimethyl Acetylenedicarboxylate (DMAD, 6)
A mixture of dimethyl acetylenedicarboxylate (DMAD, 6a) and (Z)-N-unsubstituted/ substituted-2-(2-oxoacenaphthylen-1-(2H)-ylidene)thiosemicarbazones 5a-e, was refluxed in absolute EtOH for 20-30 min. The reaction revealed the complete disappearance of compounds 5a-e and 6a to give compounds 7a-e in 70-76% yields (Scheme 3). Surprisingly, only in the case of allyl derivative 5d, an unexpected compound 8d was obtained in 10% yield (Scheme 3). Different spectroscopic data were insufficient to determine completely the correct structure of this compound. Different nucleophilic sites on thiosemicarbazone derivatives 5a-e were expected to participate in the reaction and formation of the product. Nucleophilic attack of lone pair of electrons of the sulfur atom in the thione group in 5a-e to the acetylenic carbon in 6a would give the Zwitter ions 9a-e. Neutralization of 9a-e would give the intermediate 10a-e. Subsequently another nucleophilic attack from a lone pair of electrons of 2 NH or 4 NH on CO2Me; would yield the corresponding 4thiazolidinones 7a-e and/or 12a-e via the loss of methanol (Scheme 4). The 1 H and 13 C-NMR spectral data (see details in Supplementary Materials) were used as an important tool for excluding some 4-thiazolidinones 7a-e and/or 12a-e via the loss of methanol (Scheme 4). The 1 H and 13 C-NMR spectral data (see details in Supplementary Materials) were used as an important tool for excluding some alternative structures. Furthermore, in the case of 7a-e and 12a-e, X-ray analyses were used as a useful tool to determine the correct structure and to prove that the 1,3-thiazolidine-4-ones 7a-e were formed rather than 12a-e.
Molecules 2019, 24, x FOR PEER REVIEW 5 of 19 alternative structures. Furthermore, in the case of 7a-e and 12a-e, X-ray analyses were used as a useful tool to determine the correct structure and to prove that the 1,3-thiazolidine-4-ones 7a-e were formed rather than 12a-e. Scheme 4. The mechanism describes the formation of compounds 7a-e and 12a-e.
For example, the IR spectrum of 7a showed absorption bands at ν = 3489 cm −1 for the NH group, 1715, 1696 cm −1 for C=O as well as 1623 and 1609 cm −1 for C=N and Ar-C=C groups. The 1 H-NMR spectrum of 7a clearly proved that there are two singlets one at δ = 3.81 ppm with 3H integral corresponding to one methoxy group, the other at δ = 6.73 ppm with 1H integral relating to vinyl-CH group. Acenaphthequinone protons resonated at δ = 7.85-8.35 ppm due to six aromatic protons. A broad NH group also resonated as a singlet at 13.46 ppm. Further, 13 (Table 1 and Figure 2). The elemental analysis of 7a suggests that it has C18H11N3O4S formula. This was further investigated from mass spectrum giving a molecular ion at m/z = 365 (10%). For example, the IR spectrum of 7a showed absorption bands at ν = 3489 cm −1 for the NH group, 1715, 1696 cm −1 for C=O as well as 1623 and 1609 cm −1 for C=N and Ar-C=C groups. The 1 H-NMR spectrum of 7a clearly proved that there are two singlets one at δ = 3.81 ppm with 3H integral corresponding to one methoxy group, the other at δ = 6.73 ppm with 1H integral relating to vinyl-CH group. Acenaphthequinone protons resonated at δ = 7.85-8.35 ppm due to six aromatic protons. A broad NH group also resonated as a singlet at 13.46 ppm. Further, 13 Figure 2). The elemental analysis of 7a suggests that it has C 18 H 11 N 3 O 4 S formula. This was further investigated from mass spectrum giving a molecular ion at m/z = 365 (10%).   Additionally, the structure of (Z)-methyl 2-((Z)-3-allyl-4-oxo-2-((E)-(2-oxoacenaphthylen-1 (2H)-ylidene)hydrazono)thiazolidin-5-ylidene)acetate (7d) has been unambiguously confirmed via a single-crystal X-ray structure analysis ( Figure 3). The characteristic properties of compound 7d are that the C2-N13 and C15-N14, double bonds (note that the crystallographic numbering does not correspond to the systematic IUPAC numbering rules) exhibit bond lengths of 1.2912 (16) Å and 1.2892 (16) Å, respectively, that are a little shorter than C = N δ bonds due to high resonance in 7d. The dihedral angle of N19-C15-N14-N13 is 178.82 (9)°, showing that it has a trans configuration relating to N19. Bond lengths C1-C2 and N13-N14 are 1.5345 (16) and 1.3950 (14), respectively, which are shorter than the corresponding C-C and N-N single bonds due to high resonance in this compound. From X-ray analysis, it was also observed that the thiazolidine C = O has a cisoid geometry regarding to vinyl CH [torsion angle O18-C18-C17-C23 −2.2 (2)°]. Additionally, the structure of (Z)-methyl 2-((Z)-3-allyl-4-oxo-2-((E)-(2-oxoacenaphthylen-1(2H)ylidene)hydrazono)thiazolidin-5-ylidene)acetate (7d) has been unambiguously confirmed via a single-crystal X-ray structure analysis ( Figure 3). The characteristic properties of compound 7d are that the C2-N13 and C15-N14, double bonds (note that the crystallographic numbering does not correspond to the systematic IUPAC numbering rules) exhibit bond lengths of 1.2912 (16) Å and 1.2892 (16) Å, respectively, that are a little shorter than C = N δ bonds due to high resonance in 7d. The dihedral angle of N19-C15-N14-N13 is 178.82 (9) • , showing that it has a trans configuration relating to N19. Bond lengths C1-C2 and N13-N14 are 1.5345 (16) and 1.3950 (14), respectively, which are shorter than the corresponding C-C and N-N single bonds due to high resonance in this compound. From X-ray analysis, it was also observed that the thiazolidine C = O has a cisoid geometry regarding to vinyl CH [torsion angle O18-C18-C17-C23 −2.2 (2) • ]. A literature survey revealed that, the tetramerization reaction is one of the most fascinating reactions of both dialkyl acetylenedicarboxylic acid derivatives occurring at 25 °C for several days or by heating it alone or in solution for several hours [51][52][53]. Furthermore, trimer [54] and dimer [55] forms were reported for compound 6a. Recently, Huang et al. [56] have reported the reaction of 2,2′bis(azaphosphindole) with four equivalents of 6a in THF at room temperature to afford a tetramer complex of 6a with 2,2′-bis(azaphosphindole).
The structure of 8d was resolved by using single crystal X-ray analysis and it was found that it is tetramethyl 5-(2-(((Z,E)-N-allyl-N'-(2-oxoacenaphthylen-1(2H)-ylidene)carbamo-hydrazonoyl)thio)-1,2,3-tris(methoxycarbonyl)cyclopropyl)-4-methoxy-7-oxabicyclo-[2.2.1]hepta-2,5-diene-1,2,3,6-tetracarboxylate (8d) (Figure 4). To our best knowledge, it would be the first X-ray structure of that tetramer of 6a. It is interesting to note that only one diastereomer was isolated (at least being isolated).   The unusual reactivity of 6a towards allyl derivative of thiosemicarbazones 5d obviously involves four molecules of 6 reacting with one molecule of 5d. The mechanism presumably begins via dimerization of 6a (acting as dienophile and as 1,3-dipole) to afford 13, which then rearranged to give 14. Addition of the third molecule of 6a to the intermediate 14 would give the intermediate 15, which would be neutralized to give cyclopropene 16 (Scheme 5). Diels-Alder reaction of 16 and the fourth molecule of 6a, yield the complex 17 [56] (Scheme 5). Subsequently, a nucleophilic attack of thione-lone pair of thiosemicarbazone 5d to the double bond of the cyclopropene ring would give the Zwitter ion 18, which would be neutralized to give compound 8d (Scheme 5). The unusual reactivity of 6a towards allyl derivative of thiosemicarbazones 5d obviously involves four molecules of 6 reacting with one molecule of 5d. The mechanism presumably begins via dimerization of 6a (acting as dienophile and as 1,3-dipole) to afford 13, which then rearranged to give 14. Addition of the third molecule of 6a to the intermediate 14 would give the intermediate 15, which would be neutralized to give cyclopropene 16 (Scheme 5). Diels-Alder reaction of 16 and the fourth molecule of 6a, yield the complex 17 [56] (Scheme 5). Subsequently, a nucleophilic attack of thione-lone pair of thiosemicarbazone 5d to the double bond of the cyclopropene ring would give the Zwitter ion 18, which would be neutralized to give compound 8d (Scheme 5).

Scheme 5.
Plausible mechanism for the synthesis of compound 8d.
The formation of a complex structure may be further used as a Supplementary tool for the formation of 1,3-thiazolidinone derivative 7d, which might be attributed to the instability of 8d during the course of a reaction. It can be also suggested that another nucleophilic attack of NH lonepair of compound 8d to one of the carbonyl ester group of the cyclopropane ring afforded the intermediate 19 that would be rearranged giving the 4-thiazolidinone 7d and 20 (Scheme 6). However, compound 20 was unfortunately not isolated.
By analogy, the mechanism of formation of compounds 7a-e would be similar to that for the formation of  We aimed to synthesize thiazolidinones bearing a paracyclophanyl moiety; accordingly, we reacted 4-acetyl [2.2]paracyclophanylidene-thiosemicarbazone derivatives 22a and 22f with DMAD, 6a and DEAD, 6b (Scheme 8). By adaptation of the previously mentioned procedure, the expected 1,3-thiazolidinones 26-29 were obtained in good yields (Scheme 8). Depending on 1 H-NMR and 13 C-NMR, various alternative structures were ruled out. In order to distinguish between the expected 1,3thiazolidinone derivatives, a single crystal of 28 was obtained as ethyl 2-((Z)-2-(((E)-1-(1,4(1,4)dibenzenacyclohexaphane-1 2 -yl)ethylidene)hydrazine-ylidene)-4-oxothiazolidin-5-yl)acetate ( Figure  6).  Prolonged heating of 25 with either 6a or 6b under the aforementioned conditions failed to give either a mono-or a bis-thiazolidinone structure. Either the sensitivity of such layered molecules towards light and heat to undergo dimerization and/or steric factors might cause the reaction not to occur.
By analogy, the mechanism of formation of compounds 7a-e would be similar to that for the formation of  Prolonged heating of 25 with either 6a or 6b under the aforementioned conditions failed to give either a mono-or a bis-thiazolidinone structure. Either the sensitivity of such layered molecules towards light and heat to undergo dimerization and/or steric factors might cause the reaction not to occur.
By analogy, the mechanism of formation of compounds 7a-e would be similar to that for the formation of  Scheme. 9. Mechanism described the formation of compounds 26-29.

Chemistry
Melting points (mp's) were recorded on a Gallenkamp melting point apparatus (Gallenkamp, UK) using open capillaries and were uncorrected. NMR data were recorded on Bruker AM 400 or AV400 spectrometers (Bruker, Rheinstetten, Germany), at 400 MHz for 1 H and 100 MHz for 13 C. Chemical shifts were reported in ppm from tetramethylsilane using solvent resonance in CDCl3 or DMSO-d6 solutions as the internal standard. The 13 C-NMR signals were assigned on the basis of DEPT 135/90 spectra. The mass spectra were obtained on Finnigan MAT 312) (Germany) instrument using electron impact ionization (70 eV). The IR spectra were recorded on Bruker Alpha FT-IR instrument (Germany) with samples prepared as potassium bromide pellets. Thin-layer chromatography (TLC) was performed on precoated plates (silica gel 60 PF254), and zones were visualized with ultraviolet (UV) light. Elemental analyses for C, H, N were carried out with Elementar 306. Compounds 5a-e were synthesized by refluxing solutions of acenaphthequinone 1 (1.82 g, 10 mmol) in absolute EtOH (100 mL) containing triethylamine (0.5 mL) and different solutions of thiosemicarbazide derivatives 2a-e for 3-5 h. The products were left to stand, and then collected by filtration after precipitation with ethanol. The resulting solid was recrystallized from the stated solvents to give yellow to orange crystals.

Chemistry
Melting points (mp's) were recorded on a Gallenkamp melting point apparatus (Gallenkamp, UK) using open capillaries and were uncorrected. NMR data were recorded on Bruker AM 400 or AV400 spectrometers (Bruker, Rheinstetten, Germany), at 400 MHz for 1 H and 100 MHz for 13 C. Chemical shifts were reported in ppm from tetramethylsilane using solvent resonance in CDCl 3 or DMSO-d 6 solutions as the internal standard. The 13 C-NMR signals were assigned on the basis of DEPT 135/90 spectra. The mass spectra were obtained on Finnigan MAT 312) (Germany) instrument using electron impact ionization (70 eV). The IR spectra were recorded on Bruker Alpha FT-IR instrument (Germany) with samples prepared as potassium bromide pellets. Thin-layer chromatography (TLC) was performed on precoated plates (silica gel 60 PF 254 ), and zones were visualized with ultraviolet (UV) light. Elemental analyses for C, H, N were carried out with Elementar 306. Compounds 5a-e were synthesized by refluxing solutions of acenaphthequinone 1 (1.82 g, 10 mmol) in absolute EtOH (100 mL) containing triethylamine (0.5 mL) and different solutions of thiosemicarbazide derivatives 2a-e for 3-5 h. The products were left to stand, and then collected by filtration after precipitation with ethanol. The resulting solid was recrystallized from the stated solvents to give yellow to orange crystals. (Z)-N-Ethyl-2-(2-oxoacenaphthylen-1(2H)-ylidene)hydrazinecarbothioamide (5e). Yield: (2.03 g, 72%); yellow crystals (EtOH), m.p.: 195-196 • C; [47].

Reactions of 2-Oxoacenaphthylidene Thiosemicarbazone Derivatives with 6a
A mixture of 2-oxoacenaphthylidene thiosemicarbazones (5a-e, 1 mmol) in absolute ethanol (50 mL) was refluxed with 6a for 20-30 min and the reaction was monitored by TLC analysis. A yellow precipitate of 7a-e was formed, and then the reaction mixture was filtered and washed with a small amount of ethanol. The obtained precipitates were crystalized in ethanol to give yellow crystals of 1,3-thiazolidin-4-ones 7a-d. In addition, the filtrate was left to stand at room temperature after separation of the precipitates 7a-e and, in the case of 7d, fine crystals of 8d were collected after filtration).      (15), 153 (100) 136 (64)

3.2.
Single Crystal X-ray Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C 2 H 5 OH (ethanol), a single crystal of 7d was obtained by recrystallization from C 2 H 5 OH (ethanol), a single crystal of 8d was obtained from C 2 H 5 OH (ethanol), 25 from CH 3 CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH 3 OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O) free). Semi-empirical absorption corrections were applied. 1H, NH-thiazole). 13

3.2.
Single Crystal X-ray Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O) free). Semi-empirical absorption corrections were applied. Ǻ  Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single cr of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obta from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obta acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray ana were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD det at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Met (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-(full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N free). Semi-empirical absorption corrections were applied. Ǻ (ethanol), a single crystal of 8d was obtained (acetonitrile), and a single crystal of 28 was obtained CH3OH

Single Crystal X-ray
(methanol). The single-crystal X-ray analyses ffractometer with Photon100 or Photon II CPAD detector Å). Direct Methods (SHELXS [58] or Dual Space Methods tion and refinement was carried out using SHELXL-2014 ogen atoms were refined using a riding model  gle Crystal X-ray Structure Determination of 5a, 7d, 8d, 25 and 28 single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal as obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained 2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained hthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses arried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods XT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 atrix least-squares on

Single Crystal X-ray Structure Determination of 5a, 7d, 8d, 25 and 28
A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on

Single Crystal X-ray Structure Determination of 5a, 7d, 8d, 25 and 28
A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on    Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on    Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crysta of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyse were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detecto at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Method (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on   Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethano of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal o from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of acenaphthequinone recrystallization from CH3OH (methanol). The single-cryst were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Du (SHELXT [59]) were used for structure solution and refinement was carried out us (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding free). Semi-empirical absorption corrections were applied. tal X-ray Structure Determination of 5a, 7d, 8d, 25 and 28 rystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal ined by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained none recrystallization from CH3OH (methanol). The single-crystal X-ray analyses t on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector u-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods were used for structure solution and refinement was carried out using SHELXL-2014 st-squares on  re Determination of 5a, 7d, 8d, 25 and 28 obtained by recrystallization from C2H5OH (ethanol), a single crystal allization from C2H5OH (ethanol), a single crystal of 8d was obtained rom CH3CN (acetonitrile), and a single crystal of 28 was obtained ization from CH3OH (methanol). The single-crystal X-ray analyses 8 Venture diffractometer with Photon100 or Photon II CPAD detector (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods tructure solution and refinement was carried out using SHELXL-2014  Structure Determination of 5a, 7d, 8d, 25 and 28 tal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal d by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained hanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained e recrystallization from CH3OH (methanol). The single-crystal X-ray analyses n a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods re used for structure solution and refinement was carried out using SHELXL-2014 squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model  A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O In the 2nd molecule the vinyl moiety is disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphthylene moiety shows high Uij-values, probably disordered, but the disorder is not resolved. Use of constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restraint.

X-ray
, b = 15.1023 (6) A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O In the 2nd molecule the vinyl moiety is disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphthylene moiety shows high Uij-values, probably disordered, but the disorder is not resolved. Use of constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restraint.
, c = 22.3027 (8) A single crystal of 5a was obtained by recrystallization from C2H5OH (ethano of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal o from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of acenaphthequinone recrystallization from CH3OH (methanol). The single-cryst were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Du (SHELXT [59]) were used for structure solution and refinement was carried out us (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding free). Semi-empirical absorption corrections were applied. Ǻ Compound 5a (SB1184_HY): C13H9N3OS, Mr = 255.29 g mol −1 , orange blocks, size mm, monoclinic, space group P21/c (no.14), a = 6.3357 (2) Ǻ, b = 18.2558 (7)  In the 2nd molecule th disordered, disordered atoms refined isotropically. In the second molecule the moiety shows high Uij-values, probably disordered, but the disorder is not constraints (EADP) and restraints (SADI) for the refinement as well as a general RI  Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O In the 2nd molecule the vinyl moiety is disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphthylene moiety shows high Uij-values, probably disordered, but the disorder is not resolved. Use of constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restraint.  Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O) free). Semi-empirical absorption corrections were applied. Ǻ In the 2nd molecule the vinyl moiety is disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphthylene moiety shows high Uij-values, probably disordered, but the disorder is not resolved. Use of constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restraint.  Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was ob from C2H5OH (ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was ob acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray an were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD d at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space M (SHELXT [59]) were used for structure solution and refinement was carried out using SHELX (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H free). Semi-empirical absorption corrections were applied. Ǻ In the 2nd molecule the vinyl mo disordered, disordered atoms refined isotropically. In the second molecule the oxacenapht moiety shows high Uij-values, probably disordered, but the disorder is not resolved. U constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restrain −3 . In the 2nd molecule the vinyl moiety is disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphthylene moiety shows high Uij-values, probably disordered, but the disorder is not resolved. Use of constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restraint.  Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obtained from C2H5OH

Single Crystal X-ray
(ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obtained acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray analyses were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD detector at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Methods (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL-2014 (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H (N, O) free). Semi-empirical absorption corrections were applied. Ǻ In the 2nd molecule the vinyl moiety is disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphthylene moiety shows high Uij-values, probably disordered, but the disorder is not resolved. Use of constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restraint.  Structure Determination of 5a, 7d, 8d, 25 and 28 A single crystal of 5a was obtained by recrystallization from C2H5OH (ethanol), a single c of 7d was obtained by recrystallization from C2H5OH (ethanol), a single crystal of 8d was obt from C2H5OH

Single Crystal X-ray
(ethanol), 25 from CH3CN (acetonitrile), and a single crystal of 28 was obt acenaphthequinone recrystallization from CH3OH (methanol). The single-crystal X-ray ana were carried out on a Bruker D8 Venture diffractometer with Photon100 or Photon II CPAD de at 123K using Cu-Kα radiation (λ = 1.54178 Å). Direct Methods (SHELXS [58] or Dual Space Me (SHELXT [59]) were used for structure solution and refinement was carried out using SHELXL (full-matrix least-squares on F 2 ) [59]. Hydrogen atoms were refined using a riding model (H ( free). Semi-empirical absorption corrections were applied. Ǻ In the 2nd molecule the vinyl moi disordered, disordered atoms refined isotropically. In the second molecule the oxacenaphth moiety shows high Uij-values, probably disordered, but the disorder is not resolved. U constraints (EADP) and restraints (SADI) for the refinement as well as a general RIGU restrain