反应详情

The procedure is as in Example 1, but using 1.04 g of 2-[3-(3-methylphenyl)ureido]acetic acid, 1.8 g of tert-butyl (RS)-2-anilino-2-(3-bromophenyl)acetate and 0.36 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: methanol/dichloromethane (1/99 by volume)], using an excess pressure of 40 kPa of nitrogen and collecting 10-cm3 fractions. Fractions 11 to 17 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. and the residue obtained is recrystallized from cyclohexane. 1.4 g of tert-butyl (RS)-2-(3-bromophenyl)-2-{2-[3-(3-methylphenyl)ureido]-N-phenylacetamido}acetate melting at 103° C. are then obtained.

1. customobtained
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 cyclohexane