反应详情

The procedure is as in Example 1, but using 2.1 g of 2-[3-(3-methylphenyl)ureido]acetic acid, 3.2 g of tert-butyl (RS)-2-anilino-2-(2-chlorophenyl)acetate and 0.72 cm3 of thionyl chloride as starting materials. The product obtained is purified by chromatography on 100 g of silica (0.04-0.063 mm) contained in a column 3 cm in diameter [eluent: dichloromethane/methanol (99/1 by volume)], using an excess pressure of 40 kPa of nitrogen and collecting 10-cm3 fractions. Fractions 7 to 15 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. and the residue obtained is recrystallized from a mixture of acetonitrile and isopropyl ether (10/90 by volume). 2 g of tert-butyl (RS)-2-(2-chlorophenyl)-2-{2-[3-(3-methylphenyl)ureido]-N-phenylacetamido}acetate melting at 181° C. are then obtained.

1. customThe product obtained
2. customis purified by chromatography on 100 g of silica (0.04-0.063 mm)
3. customcollecting 10-cm3 fractions
4. concentrationconcentrated to dryness under reduced pressure (2.7 kPa) at 40° C.
5. customthe residue obtained
6. customis recrystallized from a mixture of acetonitrile and isopropyl ether (10/90 by volume)