Dimethylformamide → N-Benzyl-5-chloro-3-phenyl-2H-isoindole-1-carboxamide

Participants

Reaction Conditions

Reaction Steps

A solution of 36.1 g. of 1-benzyl-7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one in 300 ml. of dimethylformamide is treated under an atmosphere of argon at room temperature with 0.11 mol. of sodium hydride (4.8 g of a 55% dispersion in mineral oil). The mixture is first heated to 60° C. over a period of about 30 minutes, and then stirred for 1 hour at this temperature for an additional 1 hour at 70° C. After cooling, 10 ml. of water are added dropwise and the mixture is poured into 3 liters of ice-water. After the addition of 100 g. of sodium chloride, the separated product is extracted with methylene chloride. The organic phase is washed with a saturated solution of sodium chloride, dried over sodium sulfate and concentrated to dryness. The resulting oily residue is chromatographed on 1000 g. of silica gel with methylene chloride/ethyl acetate (4:1) as the eluant. The homogeneous fractions are combined, evaporated and triturated with a small amount of ether, and there is obtained 5-chloro-3-phenylisoindole-1-carboxylic acid benzylamide in the form of fibrous, greenish crystals; melting point 202°-204° C. (decomposition). Recrystallization from chloroform does not increase the melting point.

Provenance & Evidence