Benzyl Alcohol → 2-(N-carbobenzyloxyaminosulfonyl)aminopentanoic acid methyl ester

Participants

Reaction Steps

To a stirred solution of 7.36 ml (84.9 mmol) of chlorosulfonyl isocyanate in 150 ml of methylene chloride was added benzyl alcohol (8.82 ml, 84.7 mmol) at 0°-5° C. After stirring the above solution for 1.5 hours at this temperature, a solution of 15.62 g (93.25 mmol) of 2-amino-pentanoic acid methyl ester hydrochloride in 500 ml of methylene chloride containing triethylamine (25.54 g, 0.2528 mol) was added at 0°-5° C., and the resulting mixture was stirred overnight allowing the mixture to warm to room temperature. The reaction mixture was poured into 600 ml of 10% aq. HCl solution, saturated with sodium chloride, and the organic layer was separated. The aqueous layer was extracted with methylene chloride/ethyl acetate (4:1, 2×200 ml) and the combined organic layer was washed with brine, dried and concentrated in vacuo to yield 28.2 g (87.6%) of 2-(N-carbobenzyloxyaminosulfonyl) aminopentanoic acid methyl ester (Formula XIV: R=CH3, R1 =H; R2 =propyl; R3 =H) as a solid, m.p. 76°-78° C.

Provenance & Evidence