4-Aminophenol → (6S)-4-(4-Chlorophenyl)-N-(4-hydroxyphenyl)-2,3,9-trimethyl-6H-thieno(3,2-f)(1,2,4)triazolo(4,3-a)(1,4)diazepine-6-acetamide

Participants

Reaction Conditions

Reaction Steps

(S)-4-(4-Chlorophenyl)-2,3,9-trimethyl-6H-thieno[3,2-f]-[1,2,4]triazolo[4,3-a][1,4]diazepine-6-acetic acid (3.0 g) and triethylamine (1.2 ml) are added to a mixed solvent of dimethylformamide (30 ml) and tetrahydrofuran (15 ml). The mixture is cooled to -10° C., and pivaloyl chloride (1.0 ml) is dropwise added at said temperature. Thirty minutes later, a solution of 4-aminophenol (0.99 g) in dimethylformamide (20 ml) is dropwise added at said temperature, and the mixture is stirred at room temperature for 7.5 hours. After the completion of the reaction, tetrahydrofuran is distilled away, and saturated brine (200 ml) is added. The mixture is extracted with ethyl acetate, and the organic layer is washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue is purified by silica gel column chromatography (ethyl acetate: methanol=10:1) and crystallized from isopropyl alcohol to give 620 mg of (S)-N-(4-hydroxyphenyl)-4-(4-chlorophenyl)-2,3,9-trimethyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine-6-acetamide as pale-pink powdery crystals, melting point 215°-220° C.

Provenance & Evidence