2,4-disubstituted-5-cyano-1,6-dihydro-6-oxo-1-pyrimidineacetic acid aldose reductase inhibitors

The process for producing the compounds of formula (I) ##STR33## wherein R.sup.1 is lower alkyl having 1 to 3 carbon atoms, cyclo(lower)alkyl having 3 to 6 carbon atoms, naphthalenyl, or halogen substituted naphthalenyl;

• R is -SR.sup.2 wherein R.sup.2 is lower alkyl having 1 to 6 carbon atoms, phenylmethyl, halogen substituted phenylmethyl, or cyclohexylmethyl or R is R.sup.5 wherein R.sup.5 is lower alkyl having 1 to 3 carbon atoms, phenyl, or naphthalenymethyl;
• and the pharmaceutically acceptable salts thereof which comprises N-alkylating the compounds of formula ##STR34## wherein R and R.sup.1 are as defined above with X-CH.sub.2 -COOR.sup.6, wherein R.sup.6 is lower alkyl having 1 to 4 carbon atoms, and X is bromine or iodine in the presence of the strong base sodium hydride in tetrahydrofuran or dimethoxyethane solvent to produce the compounds of formula ##STR35## wherein R, R.sup.1 and R.sup.6 are as defined above and hydrolyzing the ester group of said compound with base to produce the desired compounds of formula (I).