| abstract |
2-Aminothiophene-3-carboxamides are converted to oxamates or fumaramides by acylation of the amino group. Cyclization yields thieno[2,3-d]pyrimidines which may also be prepared from the corresponding oxazines. Compounds illustrative of those having inhibitory action on the immediate hypersensitivity reaction in mammals are N-[3-(aminocarbonyl)-4,5,6,7-tetrahydrobenzo[b]thien-2-yl]oxamic acid, ethyl 5,6,7,8-tetrahydro-4-oxo-4H-benzothieno[2,3-d][1,3]oxazine-2-carboxylate, and ethyl 3,4-dihydro-6-ethyl-4-oxothieno[2,3-d]pyrimidine-2-carboxylate. |