THIENO-COMPOUNDS .10. SYNTHESIS OF 3,5,6-TRISUBSTITUTED 2-ALKYLTHIO-3,4-DIHYDRO-4-OXOTHIENO[2,3-D]PYRIMIDINES

The preparation of a number of new 2-alkylthio-3,4-dihydro-4-oxothieno[2,3-d]pyrimidines is described. Starting from 2-aminothiophene derivatives and thiophosgen the corresponding isothiocyanates were prepared, which react with aminoacids or their esters to give N,N'-disubstituted thioureas. These compounds were cyclized in a basic solution to form 1,2,3,4-tetrahydro-4-oxo-2-thioxothieno[2,3-d]pyrimidines having a carboxylic group in position 3. By different alkylating agents S-alkylated and esterified products can be obtained.