Lawesson's reagent → (S)-8-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carbonitrile

Participants

Reaction Steps

A mixture of 6.32 g (20 mmol) of (S)-8-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxamide, 5.68 g (14 mmol) of 2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulphide and 100 ml of toluene is heated to boiling under reflux for 4.5 hours. The solution obtained is then evaporated in vacuo and the residue is chromatographed on silica gel while eluting with ethyl acetate. After recrystallization from methylene chloride/ethyl acetate there is obtained (S)-8-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carbonitrile of melting point 237°-238°.

Provenance & Evidence