tert-butyl 2-(4-chloroanilino)acetate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure used is similar to that described in Example 17, but starting with tert-butyl 2-[(4-chlorophenyl)amino]acetate (1.8 g), 2-[3-(3-methylphenyl)-ureido]acetic acid (1.56 g) and thionyl chloride (0.89 g). The product obtained is purified by chromatography on silica (0.04-0.063 mm) (60 g) contained in a column 2.5 cm in diameter [eluent: cyclohexane/ethyl acetate (80:20 by volume)], using an excess pressure of nitrogen of 40 kPa and collecting 20-cc fractions. Fractions 21 to 25 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. After crystallisation in acetonitrile, tert-butyl 2-{N-(4-chlorophenyl)-2-[3-(3-methylphenyl)ureido]acetamido}acetate (0.5 g), m.p. 125° C., is obtained. The product obtained is purified by chromatography on silica (0.04-0.063 mm) (60 g) collecting 20-cc fractions concentrated to dryness under reduced pressure (2.7 kPa) at 40° C After crystallisation in acetonitrile