Lithium Hydroxide → 1-[5-((S)-1-{(S)-2-[(S)-2-(tert-Butoxycarbonyl-methyl-amino)-propionylamino]-3-methyl-butyryl}-pyrrolidin-2-yl)-pyridin-3-yl]-1H-indole-3-carboxylic acid

Participants

Reaction Steps

To a solution of 1-[5-((S)-1-{(S)-2-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-3-methyl-butyryl}-pyrrolidin-2-yl)-pyridin-3-yl]-1H-indole-3-carboxylic acid ethyl ester (I-2A-2c: 0.29 g, 0.46 mmol) in THF (1 mL) and MeOH (0.3 mL) was added a solution of LiOH (0.035 g, 0.80 mmol) in water (0.3 mL). The resulting mixture was stirred at room temperature for 5 hours. More LiOH (0.065 g, 2.70 mmol) was added and stirring continued for overnight. The reaction mixture was then concentrated under reduced pressure to remove all organic solvents, then diluted with water. To this mixture 1 M HCl was added dropwise until pH=4. The white precipitate formed was filtered and dried in vacuo to give the titled compound as a white powder (0.19 g, 70%).

Provenance & Evidence