反应详情

To a mixture of phenylglycine-o-carboxylic acid obtained in Example 30 (2.30 g, 11.8 mmol) and NaOAc (3.75 g, 47.1 mmol) in DMF (29 mL) was slowly added Ac2O (11.7 mL, 118 mmol) and the mixture was refluxed for 2 hours. After cooling, the mixture was concentrated to 10 mL, partitioned between H2O (60 mL) and CHCl3 (120 mL), and the aqueous layer was extracted with CHCl3 (3x). The combined organics were washed with Na2CO3 (1M), H2O, brine and dried (MgSO4). Purification of the crude oil by LPLC, eluting with hexane-EtOAc (2:1), afforded 1.89 g (74%) of the title compound as a light yellow powder, Rf 0.34 (hexane-EtOAc 2:1), mp 79.6°-80.5° C.; 1H NMR (CDCl3) δ 8.47 (d, J=8.0, 1H), 7.72 (s, 1H), 7.55 (d, J=8.0, 1H), 7.40 (t, J=8.0, 1H), 7.31 (t, J=8.0, 1H), 2.62 (s, 3H), 2.40 (s, 3H), 13C NMR (CDCl3) δ 168.7, 167.8, 134.6, 132.8, 126.2, 123.7, 123.6, 117.4, 116.7, 113.3, 23.9, 21.0; MS (EI, m/z) 217 (M+).

1. temperaturethe mixture was refluxed for 2 hours
2. temperatureAfter cooling
3. concentrationthe mixture was concentrated to 10 mL
4. custompartitioned between H2O (60 mL) and CHCl3 (120 mL)
5. extractionthe aqueous layer was extracted with CHCl3 (3x)
6. washThe combined organics were washed with Na2CO3 (1M), H2O, brine
7. dry with materialdried (MgSO4)
8. customPurification of the crude oil by LPLC
9. washeluting with hexane-EtOAc (2:1)