880649-84-3Relevant articles and documents
Fluorine-containing heterocycles: Part I. Synthesis of new 7-(2-thienyl)-9-trifluoromethylpyrido[3′,2′:4,5]thieno[3,2-d] pyrimidines and related fused tetracyclic systems
Bakhite, Etify A.,Abdel-Rahman, Abdu E.,Al-Taifi, Elham A.
, p. 147 - 154 (2007/10/03)
3-amino-6-(2-thienyl)-4-trifluoromethylthieno[2,3-b]pyridine-2-carboxamide (3) and 2-carbonitrile analogue 5 were prepared by reaction of 3-cyano-6-(2-thienyl)-4-trifluoromethylpyridine-2(1H)-thione (1) with chloroacetamide or chloroacetonitrile respectively. Heating compound 3 with triethyl orthoformate led to the formation of pyridothienopyrimidinone derivative 6. Reaction of 6 with phosphorus oxychloride produced 4-chloropyrimidine derivative 7 which underwent some nucleophilic displacements upon treatment with thiourea, piperidine, morpholine or hydrazine hydrate to give the target 4-substituted pyridothienopyrimidines 8, 10a, 10b and 11 respectively. Reaction of compound 8 with methyl iodide or ethyl chloroacetate gave compounds 9a,b. The condensation of 3-amino-6-(2-thienyl)-4- trifluoromethyl-thieno[2,3-b]pyridine-2-carbonitrile (5) with triethyl orthoformate led to the formation of methanimidate derivative 21 which upon treatment with hydrazine hydrate gave the target 3-amino-3,4-dihydro-4-imino-7- (2-thienyl)-9-trifluoromethylpyrido[3′,2′:4,5] thieno[3,2-d] pyrimidine (22). The reactions of compounds 11 and 22 with some reagents namely; triethyl orthoformate, acetic anhydride, formic acid, acetic acid, acetylacetone benzaldehyde and/or diethyl malonate were carried out and their products were identified, in most cases as [1,2,4] triazolopyridothienopyrimidines via Dimroth rearrangement.
