5-Benzimidazolecarboxylic acid → 6-(1H-Benzo[d]imidazol-6-yl)-3-(3,4,5-trimethoxyphenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole
Reaction equation
[NH2:1][N:2]1[C:6]([C:7]2[CH:12]=[C:11]([O:13][CH3:14])[C:10]([O:15][CH3:16])=[C:9]([O:17][CH3:18])[CH:8]=2)=[N:5][N:4]=[C:3]1[SH:19].[N:20]1[C:24]2[CH:25]=[CH:26][C:27]([C:29](O)=O)=[CH:28][C:23]=2[NH:22][CH:21]=1>P(Cl)(Cl)(Cl)=O>[NH:22]1[C:23]2[CH:28]=[C:27]([C:29]3[S:19][C:3]4=[N:4][N:5]=[C:6]([C:7]5[CH:8]=[C:9]([O:17][CH3:18])[C:10]([O:15][CH3:16])=[C:11]([O:13][CH3:14])[CH:12]=5)[N:2]4[N:1]=3)[CH:26]=[CH:25][C:24]=2[N:20]=[CH:21]1Participants
4
Procedure
A mixture of 4-amino-3-mercapto-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole (80 mg, 0.28 mmol) and 3H-benzo[d]imidazole-5-carboxylic acid (46 mg, 0.28 mmol) in phosphoryl chloride (2 mL) was refluxed for 3 h. The solvent was evaporated and the residue was dissolved in dichloromethane (20 mL). It was neutralized with aqueous sodium carbonate. The organic layer was dried over sodium sulfate, concentrated to give 20 mg (17%) of the title compound as a solid. 1H NMR (CD3OD): 8.55 (s, 1H), 8.35 (s, 1H), 8.01-7.85 (m, 2H), 7.72 (s, 1H), 3.99 (s, 6H), 3.87 (s, 3H).