Water → 11-chlorocarbonyl-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one

Participants

Reaction Steps

To a suspension of 158.3 g (0.75 mol) of 5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one in 3 liters of dioxane, 730 ml (1.46 mol) of a 20% solution of phosgene in toluene was added dropwise within 45 minutes and the resulting mixture was then stirred for 2 hours at ambient temperature. 1.5 l of water were added, the mixture was stirred for a further 2 hours at ambient temperature and the precipitate formed was suction filtered. The product was washed thoroughly with water and dried in a circulating air dryer. Colourless crystals, m.p. 239°-240° C.

Provenance & Evidence