New synthetic approaches to bridgehead nitrogen heterocycles derived from 3-amino-2,3-dihydro-5,6-dimethyl-2-thioxothieno[2,3-d]pyrimidin-4(1H)-one and its salts

Article abstract of DOI:10.1002/jhet.5570370523

Bridgehead nitrogen heterocycles 3a, b and 6a, b containing the thieno-pyrimidine system have been prepared from the versatile intermediates 3-amino-2,3-dihydro-5,6-dimethyl-2-thioxo-thieno[2,3-d]pyrimidin-4-(1H)-one 1 and its hydrazinium or potassium sal