Patent ID: 6337400
Filing Date: 2002-01-08
Classification: C07D

Abstract:
A process for the preparation of a compound represented by the following formula (4): wherein R1 represents a C1-6 alkyl group and R4 represents a C1-6 alkyl group, aryl group or aralkyl group, which comprises reacting a compound represented by the following formula (1): â€ƒwherein R2 represents a C1-6 alkyl group, aryl group or aralkyl group and R1 has the same meaning as defined above with a orthoformate ester in the presence of an acid catalyst, which is stronger than ammonium chloride and which is selected from the group consisting of sulfuric acid, a sulfonic acid, a Lewis acid, an acidic inorganic salt, an acid resin, and a diatomaceous earth, to form a compound represented by the following formula (2): wherein R3 represents a C1-6 all group, aryl group or aralkyl group and R1 and R2 have the same meanings as defined above; reacting the resulting compound with &agr;-cyanoacetamide in a polar solvent in the presence of a base to form a compound represented by the following formula (3): wherein R1 and R2 have the same meanings as defined above or salt thereof; and then reacting the resulting compound or salt with an acrylic ester.