Lithium hydroxide, monohydrate → (S)-1-((S)-2((S)-2-(tert-butoxycarbonyl(methyl)amino)propanamido)-3-methylbutanoyl)-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid

Participants

Reaction Steps

A solution of (S)-ethyl 1-((S)-2-((S)-2-(tert-butoxycarbonyl(methyl)amino)propanamido)-3-methylbutanoyl)-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine-2-carboxylate (1.9 g, 3.99 mmol, Eq: 1.00) in THF (36 mL) and MeOH (12 mL) was cooled in an ice bath. To this solution was added a solution of lithium hydroxide monohydrate (0.5 g, 11.9 mmol, Eq: 2.99) in water (12 mL) and the cooling bath was removed. After 1 h, the reaction was quenched by adding 0.1 M aqueous KHSO4 (200 mL) and the mixture was extracted with DCM (2×100 mL). The combined DCM layers were dried over Na2SO4 and concentrated in vacuo. The residue was azeotroped with n-heptane (1×100 mL) to give of (S)-1-((S)-2-((S)-2-(tert-butoxycarbonyl(methyl)amino)propanamido)-3-methylbutanoyl)-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid (1.8 g) as a white solid, m/z=449 (M+H).

Provenance & Evidence