Phenylhydrazine → N'-phenyl-3-tert-butoxycarbonyl-2-(3-pyridyl)thiazolidine-4-carbohydrazide

Participants

Reaction Steps

A solution of 450 mg of dicyclohexylcarbodiimide in 5 ml of tetrahydrofuran was added dropwise to a mixture of 680 mg of N-tert-butoxycarbonyl-2-(3-pyridyl)thiazolidine-4-carboxylic acid, 240 mg of phenylhydrazine, 450 mg of 1-hydroxybenzotriazole and 20 ml of tetrahydrofuran with ice cooling, and the resultant mixture was stirred with ice cooling for 1 hour and then at room temperature for 12 hours. The reaction mixture was diluted with 30 ml of ethyl acetate, and the insoluble matter was filtered off. The filtrate was washed in sequence with saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate Concentration under reduced pressure gave 840 mg of N'-phenyl-3-tert-butoxycarbonyl-2-(3-pyridyl)thiazolidine-4-carbohydrazide. Trifluoroacetic acid (5 ml) was added to the thus-obtained compound, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was concentrated under reduced pressure, the residue was dissolved in ethyl acetate, and the solution was washed in sequence with saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate Concentration under reduced pressure gave crystals, which were recrystallized from ethyl acetate. Thus was obtained 180 mg of N'-phenyl- 2-(3-pyridyl)thiazolidine-4-carbohydrazide. Melting point 155° C.

Provenance & Evidence