TRANSFORMATIONS OF 5-METHYL-6-CARBETHOXY-3,4-DIHYDROTHIENOPYRIMIDINE FOR SYNTHESIS OF 4-METHOXY-, 4-ALKYLAMINO-, AND OTHER DERIVATIVES OF THIENOPYRIMIDINE

Article abstract of DOI:10.1007/BF00519143

4-Chloro derivatives of thieno<2,3-d>pyrimidine are formed by the action of phosphorus oxychloride on 5-methyl- and 5-methyl-6-carbethoxythieno<2,3-d>pyrimidin-4-ones.Action of nucleophilic reagents (methanol, sodium methylate, primary and secondary amines) on these chloro derivatives gave 4-methoxy-, 4-alkylamino-, and 4-dialkylamino substituted thieno<2,3-d>pyrimidines.It was found that 4-methoxy derivatives of thieno<2,3-d>pyrimidines undergo a thermal rearrangement into 3-methyl-substituted thieno<2,3-d>pyrimid-4-ones.In the bromination of 5-methyl-4-chloro- and 5-methyl-4-methoxy-substituted thieno<2,3-d>pyrimidines by N-bromosuccinimide, 5-bromomethyl derivatives of thieno<2,3-d>pyrimidine are formed, from which, by the action of primary and secondary amines, 5-aminomethyl-substituted thieno<2,3-d>pyrimidines were obtained.A synthesis of 1,2,3,4-tetrahydro-1,3-diazepino<4a,10-d,e>thieno<2,3-d>pyrimidines was also carried out.