反应详情

N-BOC-4-aminobenzoyl methionine methyl ester (3.53 g, 9.59 mmol) was placed into CH2Cl2 (30-35 ml) and to it was added 3M HCl/Et2O (38.4 ml). After standing a white precipitate formed. After 2 hours the solution was decanted, and the crystals were collected by centrifugation. The crystals were then washed several times with fresh ether and dried overnight on the vacuum pump. Meanwhile, the filtrate was left to stand overnight to allow additional product to precipitate. The second fraction was washed with ether and dried overnight on the vacuum pump. The total yield of pure fully deprotected material was 2.87 g (93.9%) yield. mp 158-164° C.; 1H NMR (CDCl3) 2.10 (3 H, s), 2.12-b 2.29 (1 H, m), 2.52-2.71 (1 H, m), 2.59 (2 H, t, J=7.6 Hz), 3.75 (3 H, s), 4.79 (1 H, m), 7.02 (2 H, d, J=8.6 Hz), 7.55 (2 H, d, J=8.6 Hz); 13C NMR (CDCl3) 15.23, 31.43, 31.53, 52.91, 52.43, 124.35, 130.56, 135.31, 135.76, 168.95, 173.87; HRMS calc. for C13H18N2O3 S, 282.1038, found 282.1009.

1. customformed
2. customAfter 2 hours the solution was decanted
3. customthe crystals were collected by centrifugation
4. washThe crystals were then washed several times with fresh ether
5. customdried overnight on the vacuum pump
6. waitMeanwhile, the filtrate was left
7. customto precipitate
8. washThe second fraction was washed with ether
9. customdried overnight on the vacuum pump
10. customyield