[Synthesis of 4-methyl-6-phenyl-thieno(2,3-d)pyrimidines with a formamidino- or oxalamidocarbonic acid residue with antianaphylactic activity].

3-Amino-4-methyl-6-phenyl-thieno[2,3-d]pyrimidine-2-carbonic acid alkylesters 1a, b were hydrolyzed to the potassium salt of the carbonic acid 2. Cyclization of 2 with acetanhydride yielded the tricyclic 1,3-oxazinone derivative 4. This compound reacted with pyrrolidine by different conditions of reaction to give the bisamide 7, the acetamidino carbonic acid 5 and their decarboxylated product 6. Compound 1a yielded with Vilsmeier reagents the formamidino compound 3. 3-Amino-thieno[2,3-d]pyrimidin-2-carbonitrile gave under different conditions of reaction with oxalic acid diethylester or with oxalic acid ethylester chloride the tetracyclic 4-methoxy-9-methyl-7-phenyl-thieno[2,3-d:4,5-d']dipyrimidine-2-car bonic acid methylester 10 or the N-(2-cyano-4-methyl-6-phenyl-thieno[2,3-d]pyrimid-3-yl)oxalamid ic ethylester 12. These compounds were hydrolyzed to give the carbonic acids 11 and 13. Some of the synthesized substances showed an antianaphylactic activity.