反应详情

温度

70 °C

Tin(II) chloride (12.2 g, 64.4 mmol) was added to a solution of 5.12 g (12.9 mmol) of N-(5-(4-cyanobenzyloxy)-2-nitrobenzoyl)-b-alanine ethyl ester in 40 mL of 1:1 ethyl acetate/ethanol and the mixture heated to 70° C. for 15 min, cooled, and poured into a mixture of ice water, 1N sodium bicarbonate, and ethyl acetate. 1N sodium hydroxide was added carefully until a clear solution resulted and the aqueous phase was separated and extracted with ethyl acetate. The combined organics were washed with water, brine, dried over anhydrous magnesium sulfate, and concentrated to give a dark solid that was purified by chromatography (silica gel-60, 1:1 ethyl acetate/hexane) to give 2.51 g (53%) of N-(5-(4-cyanobenzyloxy)-2-aminobenzoyl)-b-alanine ethyl ester as a light yellow solid. 1H NMR (300 MHz, CDCl3) d 7.67 (2H, d, J=8.3 Hz, NC-Ar-H2), 7.52 (2H, d, J=8.3 Hz, NC-Ar-H2), 6.94 (1H, d, J=2.9 Hz, O-Ar-H), 6.89 (1H, dd, J=2.9, 8.8 Hz, O-Ar-H), 6.78 (1H, b, N-H), 6.66 (1H, d, J=8.8 Hz, O-Ar-H), 5.04 (2H, s, ArCH2O), 4.16 (2H, q, J=7.3 Hz, OCH2CH3), 3.66 (2H, bq, J=5.8 Hz, NHCH2CH2), 2.62 (2H, t, J=5.8 Hz, NHCH2CH2), 1.27 (3H, t, J=7.3 Hz, OCH2CH3); Exact mass (FAB, M+H+) calcd for C20 H22N3O4 : 368.1610; Found: 368.1603.

1. temperaturecooled
2. customresulted
3. customthe aqueous phase was separated
4. extractionextracted with ethyl acetate
5. washThe combined organics were washed with water, brine
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated
8. customto give a dark solid
9. customthat was purified by chromatography (silica gel-60, 1:1 ethyl acetate/hexane)