ISSN:
1434-4475
Keywords:
3-Dicyanomethylene-2,3-dihydro-benzo[b]thiophene-1,1-dioxide
;
Benzo[b]thieno[2,3-d]thiophene-8,8-dioxide
;
Benzo[4,5]thieno[2,3-c]pyridazine-9,9-dioxide
;
1,2-Dihydro-1-oxo-1H-benzo[4,5]thieno[2,3-c]pyridine-9,9-dioxide
;
Benzo[4,5]thieno[2,3-c]pyridine-9,9-dioxide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary 2,3-Dihydro-3-oxo-benzo[b]thiophen-1,1-dioxide (1) reacts as CH-acidic component with amidines of orthoesters and anilines resp. to give the anilinomethylene derivates3, 4, and5. With triethyl orthoformiate the hydroxymethylene-compound7 is obtained. Anilino- and phenylhydrazino derivates8 and9 prove the carbonyl activity of1, azo-coupling leads to10, whereas treatment of1 with sulfur and malononitrile yields the benzo[b]thieno[2,3-d]thiophenes11. Introduction of substituents with active NH-functions in position 2 of the dicyanomethylene-product2, such as azocoupling, reaction with phenyl isocyanate and formation of enamines, leads to ring closure reactions between a nitrile and the NH-group. Thereby the phenyl-benzo[4,5]thieno[2,3-c]pyridazines12, the phenyl-1H-benzo[4,5]thieno[2,3-c]pyridines13 and the phenylamino-benzo[4,5]thieno[2,3-c]pyridines14 are obtained.13C and15N-NMR spectroscopy was used as proof of the ring closure reactions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00808932
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