Synthesis and Biological Active of Some Substituted 1 , 2 , 4-Triazoles and Their Fused Ring Derivatives

In this paper demonstrated the synthesis of some fused 1,2,4-triazoles derivatives ; Terphthalic acid condensated with ethanol to obtain diethyl terephthalate (1) in the presence of sulfuric acid as catalyst., the ethyl ester (1) was mixed with hydrazine hydrate is ethyl alcohol to give terephthalohydrazide (2). The hydrazide derivative (2) then reacted with ammonium thiocyanate to give yield 2,2'-terephthaloylbis(hydrazinecarbothioamide) (3). 3,4diamine-bis – 1,2,4-triazole derivative (4) was obtained by reaction of a compound (3) with hydrazine hydrate. 5,5'-(1,4-phenylene)bis(4H-1,2,4-triazole-3,4-diamine) (4) was reacted with a proper aldehyde to yield Schiff bases derivatives (5,6,7).1-(1H-[1,2,4]triazolo[4,3b][1,2,4]triazol-5-yl)-4-(3H-[1,2,4]triazolo[4,3-b][1,2,4]triazol-6-yl) benzene derivatives (8,9,10) were yielded by reaction a Schiff bases derivative with glacial acetic acid. The structures of the synthesized compounds were confirmed by physical and spectral methods.

A fused ring thiadiazoletriazole and triazoletriazole were synthesized as fallows .

Experimental
All chemicals were purchased from Flucka and BDH Chemical Ltd.The melting points were measured on an Electrothermal 9300 Engineering LTD and were uncorrected.IR spectra were recorded on Infrared Spectrophotometer Model Tensor 27, Bruker Co., Germany, using KBr discs.Synthesis of Diethyl terephthalate (13) (1) : To terphthalic acid ( 0.025 mole) in absolute ethanol (50 ml) , concentrated sulfuric acid (5 ml) was added with cooling , the mixture was refluxed for (8 hours) the solvent was evaporated and the residue then neutralized with 20% sodium bicarbonate , the ester was precipitated as white sold , filtered and recrystalized from ethanolwater(1:1) , m.p.(214 o C) , yield (80%).
hydrochloric acid (0.5ml) in ethanol (25 ml) .the mixture was refluxed for (2) hours , then cooled and the precipitate filtered and recrystallized from ethanol .The Physical Constant and chemical and spectra data of compound are given in table 1 and 3. Method A (18) : Compound (5,6 or 7) was dissolved in dry xylene (50 ml) phosphorus oxychloride (10 ml) was added and the mixture refluxed for (6-8) hours .the solvent was removed under reduced pressure , cold water was added and the precipitate filtered and recrystallized from etherpet.
Ether(3:1) , The Physical Constant and chemical and spectra data of compound are given in table 1 and 3.
Method B (19) : Compound (5,6 or 7) was dissolved in glacial acetic acid (20 ml) and stirring the mixture at 80 o C for 2 hr and then added crash ice , filtered and recrystallized from ethanolwater(1:1) , The Physical Constant and chemical and spectra data of compound are given in table 1 and 3.In this paper calculate theoretical some parameter for compound (4-10) by : 1. Draw the figer by ( Chem.3D).

Result and Discussion
In this paper the synthesis of some substituted fused ring 1,2,4-triazoles is reported .The stricture show the compounds energy for surface and according to calculation of energy of HOMO , highest occupied molecular orbital ; LUMO , lowest unoccupied molecular orbital theory in table (2), that's important factors that affect bioactivity (20) .HOMO has the priority to provide electrons , while LUMO can accept electrons first (20) .The geometry of frame compounds (4-10) is hardly influenced by the introduction of , ether the triazole ring , benzene ring or fuse ring (figure 1) .This also implies that the orbital interaction between the title heterocyclic compound and the aromatic ring or some other side of residue chains of receptors is dominated by π-π or hydrophobic interaction among the frontier molecular orbitals.
Vol   Show that increase in electron potential for chemical compounds with decreased susceptibility donor as Table (2).
Global electrophilcity Index (w) (5, 6, 7) & (8, 9, 10) Show that decreased the value of Global electrophilcity index with the decrease susceptibility Donor ,The increase in electron potential chemical spin Global electrophilcity index is the latest proof of the stability of the prepared compounds as Table ( 2 ).