N-Boc-4-chloro-D-phenylalanine → 4-Chloro-D-phenylalanine methyl ester hydrochloride

Participants

Reaction Steps

(R)-3-(4-Chloro-phenyl)-2-[4-iodo-2-(quinoxaline-5-sulfonylamino)-benzoylamino]-propionic acid. (R)-2-(tert-Butoxycarbonylamino)-3-(4-chloro-phenyl)-propionic acid was treated as in EXAMPLE 2, Part A, to produce (R)-2-amino-3-(4-chloro-phenyl)-propionic acid methyl ester hydrochloride as a white solid. This ester was coupled with 4-iodo-2-(quinoxaline-5-sulfonylamino)-benzoic acid as in EXAMPLE 1, Part C. The resulting methyl ester was hydrolyzed as in EXAMPLE 2, Part E. HPLC: RT=9.74 min. MS (ESI−): mass calcd. for C24H18ClIN4O5S, 635.97; m/z found, 635/637 [M−H]−. 1H NMR (500 MHz, CDCl3): 10.93 (d, J=12.8, 1H), 8.99 (d, J=1.6, 1H), 8.92 (s, 1H), 8.54 (d, J=7.4, 1H), 8.31 (d, J=8.5, 1H), 8.10 (s, 1H), 7.90-7.87 (m, 1H), 7.30-7.22 (m, 3H), 7.05 (d, J=8.4, 2H), 6.84 (d, J=8.2, 1H), 6.29 (d, J=7.9, 1H), 4.93-4.80 (m, 1H), 3.24 (dd, J=14.3, 5.8, 1H), 3.16 (dd, J=14.2, 5.9, 1H).

Provenance & Evidence