2-Azetidinecarboxylic acid, (S)- → (S)-5-bromo-1,10a-dihydroazeto[2,1-c][1,4]benzodiazepine-4,10(2H,9H)-dione

Participants

Reaction Steps

25 g (103 mmol) of 6-bromo-isatoic acid anhydride and 10.44 g (103 mmol) of L-azetidine-2-carboxylic acid in 100 ml of dimethyl sulphoxide are stirred at 95° for 25 minutes, the dimethyl sulphoxide is removed in vacuo and the residue is heated to 150° for 3 hours in a high vacuum. By chromatography of the resulting material on silica gel while eluting with ethyl acetate and subsequent recrystallization from ethyl acetate there is obtained (S)-5-bromo-1,10a-dihydroazeto[2,1-c][1,4]benzodiazepine-4,10(2H,9H)-dione of melting point 182°-183°.

Provenance & Evidence