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ChemicalBook CAS DataBase List N-Boc-alpha-methyl-D,L-phenylalanine
86778-91-8

N-Boc-alpha-methyl-D,L-phenylalanine synthesis

8synthesis methods
-

Yield:86778-91-8 100%

Reaction Conditions:

with triethylamine in tetrahydrofuran at 20 - 50;

Steps:

A

In a flaska-methyl-dl-phenylalanine methyl ester hydrochloride(5.lg, 22 mmol) in THF (75mL) at rt was added TEA (2.9mL, 22 mmol). The contents were filtered (removeTEA-HC1) and the filtrate treated with t-butoxycarbonyl anhydride (4.8 g, 22mmol). The mixture was placed in50 oil bath and stirred overnight. The crude mixture was poured onto EtOAc and washed with aq.NH4C1 followed by water and brine. After drying overNa2S04 and solvent removal, 6.6 g methyl methylN- (tert- butoxycarbonyl)-a-methylphenylalaninate was obtained as a white solid (quant) : 1H NMR (400 MHz, CD30D) 8 7.34 (m, 3H), 7.05 (m, 2H), 5.12 (br s, 1H), 3.74 (s, 3H), 3.34 (broad AB, J = 9.6 Hz,1H), 3.18 (AB, J = 13.6 Hz, 1H), 1.55 (s, 3H), 1.45 (s, 9H); LC-MS [M-99, loss of Boc] =194. 3.

References:

WO2005/51914,2005,A1 Location in patent:Page/Page column 60