反应详情

Following the procedure described in part E of Example 1 (R), (S)-α-[[2-[((1,1-dimethylethyl)dimethylsilyl)oxy]-2-[4-hydroxy-3-[(methylsulfonyl)amino]phenyl]ethyl]amino]-4-methoxybenzeneacetic acid was condensed with diethyl 3-chloro-4-aminobenzylphosphonate to generate the title compound. The diethyl 3-chloro-4-aminobenzylphosphonate was prepared from commercial 2-chloro-4-nitrobenzoic acid upon sequential treatment with 1) diborane in THF; 2) φ3P,CBr4 in CH2Cl2 ; 3) P(OEt)3 at 125° C.; and 4) reduction with Na2S2 O4 in THF/H2O at 100° C.

1. customat 125° C.
2. customat 100° C.