Lithium borohydride → (S)-2-(2-aminophenyl)-7-methoxy-8-(3-(((S)-7-methoxy-2-(4-methoxyphenyl)-5-oxo-5,11a-dihydro-pyrrolo[2,1-c][1,4]benzodiazepin-8-yl)oxy)propoxy)-pyrrolo[2,1-c][1,4]benzodiazepin-5(11aH)-one

Participants

Reaction Steps

A solution of Superhydride in dry tetrahydrofuran (1.0 M, 4.4 eq.) was added to a solution of the 2-analino compound 103 (300 mg) in dry tetrahydrofuran (5 mL) at −78° C. under an inert atmosphere. As reduction was proceeding slowly an aliquot of lithium borohydride (20 eq.) was added and the reaction mixture was allowed to return to room temperature. Water/ice was added to the reaction mixture to quench unreacted hydrides and the reaction was diluted with dichloromethane. The organic layer was washed sequentially with water (twice), citric acid and brine. Excess dichloromethane was removed by rotary evaporation under reduced pressure and the residue was redissolve in ethanol and water and treated with silica gel for 96 hours. The reaction mixture was vacuum filtered and the filtrate evaporated to dryness. The residue was subjected to flash column chromatography (silica gel, gradient chloroform/methanol). Pure fractions were collected and combined and excess eluent was removed by rotary evaporation under educed pressure to afford the pure product 104 (30 mg, 14% yield). LC/MS RT: 2.90 min, ES+726.09.

Provenance & Evidence