Dimethyl Sulfoxide → 10-methyl-2,3-dihydro-1H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H,11aH)-dione

Participants

Reaction Steps

A mixture of 12.3 g. of L-proline, 17.7 g. of N-methyl isatoic anhydride and 100 ml. of dimethyl sulfoxide is heated on a steam bath for 6 hours, cooled and then diluted with 250 ml. of water. The reaction mixture is extracted three times with benzene. The combined benzene layers are washed twice with water and concentrated to remove the solvent. The residue is recrystallized from ethyl acetate yielding the pure dextrorotatory isomer.

Provenance & Evidence