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

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Reaction Steps

To a stirred solution of 14.72 ml (0.17 mol) of chlorosulfonyl isocyanate in 400 ml of methylene chloride was added phenylmethanol (17.69 ml, 0.17 mol) at 0°-5° C. After stirring the above solution for 1.5 hours, a solution of 31.24 g (0.186 mol) of 2-amino-pentanoic acid methyl ester hydrochloride in 1100 ml of methylene chloride containing triethylamine (71 ml, 0.5 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 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, 2x) and the combined organic layer was washed with brine, dried over magnesium sulfate and concentrated in vacuo to yield 4.77 g (82%) of 2-(N-carbobenzyloxyaminosulfonyl)aminopentanoic acid methyl ester, (Formula XII: R=CH3 ; R1 =propyl; R2 =H; R3 =H), m.p. 76°-78° C.

Provenance & Evidence