反应详情

According to the procedure described in Example 1(b) for the preparation 3(R)-t-butoxycarbonylamino-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid benzyl ester, 2(S)-[1-(4′-cyanobiphenyl-4-yl)-1H-pyrrol-3-yl]succinic acid 4-benzyl ester (prepared as described in Example 14(b)) and 3(R)-amino-4,4-dimethyl-2-oxo-tetrahydrofuran (see Freskos, J. N. Syn Commun. 1994, 24, 557-563) were coupled using TBTU with N-methylmorpholine as the base to provide a mixture of diastereomers which were separated using chromatography on silica gel column with 0 to 5% MeOH gradient in CH2Cl2. Mixed fraction was repurified on a chromatotron using 0-2.5% MeOH/CH2Cl2 then 0-1.25% MeOH/CH2Cl2 as eluent to obtain 3(S)-[1-(4′-cyanobiphenyl-4-yl)-1H-pyrrol-3-yl]-N-(4,4-dimethyl-2-oxo-tetrahydrofuran-3(S)-yl)succinamic acid benzyl ester in 29% yield as an amorphous solid: 1H NMR (CDCl3): δ 7.75 (d, 2H, 8.1 Hz), 7.69 (d, 2H, J=8.5 Hz), 7.64 (d, 2H, J=8.5 Hz), 7.46 (d, 2H, J=8.5 Hz), 7.32 (s, 5H), 7.13 (s, 1H), 7.09 (t, 1H, J=2.2 Hz), 6.32 (s, 1H), 6.06 (d, 1H, J=7.7 Hz), 5.13 (s, 2H), 4.67 (d, 1H, J=7.7 Hz), 4.08 -4.01 (m, 3H), 3.31 (dd, 1H, J=16.9, 8.5 Hz), 2.82 (dd, 1H, J=16.7, 6.1 Hz), 1.23 (s, 3H), 0.98 (s, 3H); Anal. Calculated for C34H31N3O5•0.2 H2O: C, 72.25; H, 5.60; N, 7.43. Found: 72.32, 72.26; H, 5.88, 5.91; N, 7.07, 7.02.

1. customto provide
2. additiona mixture of diastereomers which
3. customwere separated
4. additionMixed fraction
5. customwas repurified on a chromatotron