Synthesis of some thienotetrahydroquinoline derivatives

2-Thioxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (2) was easily S-alkylated to produce alkyl mercapto derivatives 3a-g. The latter compounds were cyclized to afford thienotetrahydroquinolines 4a-g. Several pyrimidothienotetrahydroquinolines 5a-d, and 6a-d were obtained from the condensation of compounds 4c-f with different reagents. o-Aminocarbohydrazide derivative 11 was reacted with aromatic aldehydes, acetylacetone, nitrous acid and CS2 to afford compounds 12-15. Compound 24 was coupled with aryldiazonium chloride to afford arylazo derivatives 25. Also it condensed with aromatic aldehydes to give arylidene derivatives 26. The latter compounds were reacted with malononitrile to give pyrano derivative 27.