Yield:-

Steps:

II.12 N-t-butoxycarbonyl-DL-4-(methylsulfonylamino)phenylalanine

Example II-12 N-t-butoxycarbonyl-DL-4-(methylsulfonylamino)phenylalanine In the same manner as in Example II-(11-2) and Example II-(11-3) except for using N-t-butoxycarbonyl-DL-4-aminophenylalanine ethyl ester in place of N-t-butoxycarbonyl-L-4-aminophenylalanine ethyl ester and using methanesulfonyl chloride in place of benzenesulfonyl chloride, the reactions were carried out to obtain the title compound (overall yeield 84%) as white solid. ¹H-NMR (CDCl₃+DMSO-d₆) δ; 9.13 (brs, 1H), 7.21 (d, J=8.5 Hz, 2H), 7.13 (d, J=8.5 Hz, 2H), 5.18-4.48 (m, 1H), 3.30-3.08 (m, 2H), 2.92 (s, 3H), 1.42 (s, 9H). CI-MS (m/z); 259

References:

US6265418,2001,B1