351532-30-4Relevant academic research and scientific papers
Convenient Heterocyclization Reactions with 2-Functionalized-3-amino-4-aryl-5,6,7,8-tetrahydrothieno[2,3-b]quinolines; Synthesis of new Thienoquinolines, Pyridothienoquinolines, Pyranothienoquinolines and Pyrimidothienoquinolines
Bakhite, Etify A.
, p. 1201 - 1220 (2007/10/03)
The condensation of 2-acetyl-3-amino-4-aryl-5,6,7,8-tetrahydrothieno[2,3-b]quinolines (3a-c) with aromatic aldehydes afforded the corresponding chalcones 4a-e. Treatment of 4a-c with hydrazine hydrate gave pyrazolinyl derivatives 5a-c. Heating of 4a-c with orthophosphoric acid resulted in the formation of hexahydropyridothienoquinolinones 6a-c. Saponification of ethyl 3-amino-4-(p-methoxyphenyl)-5,6,7,8-tetrahydrothieno[2,3-b]quinioline-2-carboxylate (3d) gave the corresponding carboxylic acid 7 which was decarboxylated upon treatment with orthophosphoric acid at room temperature to give 3-amino-4-(p-methoxyphenyl)-5,6,7,8-tetrahydrothieno[2,3-b]quinoline (8). When the latter reaction was performed at 100 deg C, 4-(p-methoxyphenyl)-5,6,7,8-tetrahydrothieno[2,3-b]quinolin-3(2H)-one (9) was obtained. Compounds 8,9 and 3-amino-4-(p-methoxyphenyl)-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamide (3e) were transformed into novel thieno[2,3-b]quinolines and their pyrido-, pyrano- and pyrimido-fused derivatives.
