S. A. Shipilovskikh, A. Rubtsov
Mar 19, 2014
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0
Influential Citations
18
Citations
Journal
Russian Journal of Organic Chemistry
Abstract
Publications on compounds containing in the structure 3-imino-3H-furan-2-one are scarce [1]. We formerly developed a simple preparation method for a series of ethyl 2-[5-aryl-2-oxofuran-3(2H)-ylideneamino]-4,5,6,7tetrahydrobenzo[b]thiophene-3-carboxylates through an intramolecular cyclization of (Z)-4-aryl-4-oxo-2-[3(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen2-ylamino]but-2-enoic acids under the action of acetic anhydride [2]. At the same time this rare type of furan-2one derivatives is promising in view of the high reactivity and possible biologic action. The introduction into the structure of a thiophene substituent [3–5] at the imine nitrogen atom even more increases the promising qualities of these compounds. Moreover, it has been shown that the proper (Z)-4-aryl-4-oxo-2-[3-(ethoxycarbonyl)4,5,6,7-tetrahydrobenzo[b]-thiophen-2-ylamino]but-2enoic acids exhibit the biological activity exceeding the activity of drugs used in medicine [6, 7]. It was shown by an example of 5-aryl-3-arylimino3H-furan-3-one that in reaction with anilines the furan ring suffered opening giving amides of 4-aryl-4-oxo-2arylaminobut-2-enoic acids [8]. In the molecule of ethyl 2-[2-oxo-5-phenylfuran-3(2H)-ylideneamino]-4,5,6,7tetrahydrobenzo[b]thiophene-3-carboxylate (I) at least two obvious sites are present for nucleophilic attack with aliphatic amines. The reaction of ethyl 2-[2-oxo-5-phenylfuran-3(2H)ylideneamino]-4,5,6,7-tetrahydrobenzo[b]thiophene-3carboxylate (I) with amines IIа–IIc in an inert aprotic solvent afforded the corresponding ethyl 2-[(Z)-3-oxo3-phenyl-1-(carbamoyl)-prop-1-enylamino]-4,5,6,7tetrahydrobenzo[b]thiophene-3-carboxylates IIIа–IIIc.