Lithium hydroxide, monohydrate → 4-{(S)-5-(6-Bromo-2-methoxy-naphthalen-1-ylmethyl)-3-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-4-oxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepine-1-carbonyl}-benzoic acid

Participants

Reaction Steps

To a solution of 4-{(S)-5-(6-bromo-2-methoxy-naphthalen-1-ylmethyl)-3-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-4-oxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepine-1-carbonyl}-benzoic acid methyl ester (Intermediate 19) (4 g, 5.175 mmol) in THF-MeOH-water 1:1:1 (90 mL) were slowly added a solution of LiOH.H2O solution (574 mg, 13.6 m mol) in water. After 4 h the mixture was concentrated, the residue was diluted with water and acidified to pH˜3 with 1 N HCl. The mixture was extracted with ethyl acetate, the extracts were dried over sodium sulfate and evaporated. The residue was triturated with hexane to give the title compound (3.6 g, 91.58%) as an off white solid. LC-MS: 759 (M+H).

Provenance & Evidence