Synthesis of some azolothienopyrimidines from 4-chloropyrimidines

ABSTRACT

2-Methylthio-r-methyl-6-phenylthieno[2,3-d] pyrimidine-4 [3H] one and 2-methylthio- 5,6,7,8- Tetrahydrobenzothieno [2,3-d] pyrimidine 4[3H] one [l a,b] reacted with phosphorus oxychloride to give the corresponding 4-chloropyrimidine derivatives [2a,b]. compound 2[a,b] reacted with primary aromatic amines, anthranlic acid and hydrazine hydrate to give 4-substituted derivatives [3a,4a,b] and 5 [a,b], respectively. The 4-hydrazino derivatives [5a,b] could be converted into the triazolo and tetrazolo pyrimidines derivatives [6a,b] and [7] when heated with carbon disulphide and nitrous acid, respectively. 4-aminopyrimidine derivatives [8] could be synthesis by the reduction of tetrazolothieno pyrimidine [7] with zinc dust. On the other hand, compound 5[a,b] reacted with aromatic aldehydes to afford the arylhydrazones derivatives 9[a-f]. Arylhydrazone derivatives [9d-f] could be cycles to thienotriazolopyrimidine derivatives [10a-c]. Compound [5a,b] reacted with beta-diketone and ethylacetoacetate to produce 4-[1-pyrazolyl] and 4-[1-pyrazolinone] derivatives [11a,b] and [12a,b], respectively. Also, compound [5a,b] reacted with formic acid, triethylorthoformate and acetic acid to give, 13[a-d], respectively