251539-09-0Relevant articles and documents
A convenient synthesis of dithieno[2,3-b] [2,3-h]quinolines and pyrimido [4′,5′:4,5]thieno [2,3-b]thieno[2,3-h]quinolines
Geies, Ahmed A.
, p. 201 - 214 (2007/10/03)
6,7-Dihydrobenz[b]thiophen-4(5H)one (1) was condensed with 4- chlorobenzaldehyde to yield the benzylidene derivative 2 which underwent Michael addition reacting with cyanothioacetamide in methanolic sodium methoxide solution to give the thienoquinoline 3. Compound 3 was reacted with α- halo compounds to obtain the substituted thio intermediates 4a-f, which upon treatment with sodium ethoxide produce the dithienoquinoline derivatives 5a-f. Thienopyrimidothienoquinoline e.g. 9 was obtained from the reaction of ?- aminocarboxamide derivative 5d with triethyl orthoformate.