Ethyl 1-((2-amino-5-bromophenylamino)methyl)cyclopropanecarboxylate → 7-bromo-4,5-dihydrospiro[benzo[b][1,4]diazepine-3,1'-cyclopropan]-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of ethyl 1-((2-amino-5-bromophenylamino)methyl)cyclopropanecarboxylate (624 mg, 2.0 mmol) in toluene (15 mL) was added dropwise tetraisopropoxytitanium (1.2 g, 4.0 mmol). After addition was complete, the reaction was stirred for 12 hours at 90° C. The mixture was diluted with water (200 mL), extracted with ethyl acetate (200 mL). The organic layer was separated, dried by sodium sulfate, filtered and concentrated to give the crude 7-bromo-4,5-dihydrospiro[benzo[b][1,4]diazepine-3,1′-cyclopropan]-2(1H)-one (400 mg, 75%) as white solid, used for the next step without further purification.

Provenance & Evidence