反应详情

The procedure is as in Example 1, but using 11.6 g of 2-[3-(3-methylphenyl)ureido]acetic acid, 15 g of ethyl (RS)-3-anilino-3-phenylpropionate and 4 cm3 of thionyl chloride as starting materials. The product obtained is purified by chromatography on 250 g of silica (0.04-0.063 mm) contained in a column 5 cm in diameter [eluent: methanol/dichloromethane (2/98 by volume)], using an excess pressure of 40 kPa of nitrogen and collecting 75-cm3 fractions. Fractions 19 to 21 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. and the residue obtained is recrystallized from ethyl acetate. 4.5 g of ethyl (RS)-3-{2-[3-(3-methylphenyl)ureido]-N-phenylacetamido}-3-phenylpropionate melting at 146° C. are then obtained.

1. customThe product obtained
2. customis purified by chromatography on 250 g of silica (0.04-0.063 mm)
3. customcollecting 75-cm3 fractions
4. concentrationconcentrated to dryness under reduced pressure (2.7 kPa) at 40° C.
5. customthe residue obtained
6. customis recrystallized from ethyl acetate