摘要 |
There is provided a process for the preparation of 3-cyano-6-alkoxy-7-nitro-4-quinolone intermediates useful for the preparation of protein tyrosine kinase (PTK) inhibitors which are useful in the treatment of cancer of the formula: wherein R is alkyl(C<SUB>1</SUB>-C<SUB>3</SUB>) prepared by reacting a substituted anthranilate with N,N-dimethylformamide dimethyacetal to obtain a N,N-dimethylamidine which is condensed with t-butylcyanoacetate to obtain a N-(2-cyano-2-t-butoxycarbonylvinyl)anthranilate, which is hydrolyzed to yield a N-(2-cyano-2-carboxyvinyl)anthranilate followed by decarboxylating to obtain a N-(2-cyano-2-carboxyvinyl)anthranilate followed by cyclizing to obtain a 3-cyano-6-alkoxy-7-nitro-4-quinolone. |