反应详情

A mixture of 6-(2-phenoxyacetylamino)-n-hexanoic acid (made in analogy to Intermediate 15, 3.15 g, 11.9 mmol, 1.1 eq), 2-(m-nitrobenzenesulfonyl)ethanol (2.5 g, 10.8 mmol), and p-toluenesulfonic acid hydrate (0.5 g) in 100 mL of benzene was refluxed overnight with Dean-Stark trap. Thereafter water was added and the mixture was extracted with CH2Cl2. The combined organic layers were washed with saturated NaHCO3 solution, dried over MgSO4, and concentrated under reduced pressure. The residual oil was purified by column chromatography (1% MeOH in CH2Cl2) to give 4.6 g (89%) of 6-(2-phenoxy-acetylamino)-n-hexanoic acid 2-(3-nitrobenzenesulfonyl)ethyl ester.

1. temperaturewas refluxed overnight with Dean-Stark trap
2. extractionthe mixture was extracted with CH2Cl2
3. washThe combined organic layers were washed with saturated NaHCO3 solution
4. dry with materialdried over MgSO4
5. concentrationconcentrated under reduced pressure
6. customThe residual oil was purified by column chromatography (1% MeOH in CH2Cl2)