Reaction of 11Н-indeno[1,2-b]quinoxalin-2-one with semi(thiosemi)carbazides in ethanol resulted in semi(thiosemi)carbazones which at boiling in acetic anhydride underwent cylization yielding N-{3'-acetyl-3'Н-spiro[indeno[1,2-b]quinoxalin-11,2'-[1,3,4]oxa(thia)diazol]-5'-yl}acetamides. Aldol crotonic condensation of 11Н-indeno[1,2-b]quinoxalin-2-one with methyl N-(4-acetylphenyl)carbamate afforded the corresponding chalcone that at boiling in anhydrous ethanol with hydrazine hydrate for 1 h formed a spiro compound with a pyrazole ring. Five-component condensation of ninhydrin, 1,2-phenylenediamine, sarcosine, malononitrile (or ethyl cyanoacetate), and 4-formylphenyl N-phenylcarbamate in a mixture EtOH -[bmim]Br led to the formation ofwidely used for preparation of diverse derivatives exhibiting a wide range of biological activity. Its oxime is a noncytotoxic inhibitor of inflammatory cytokine and of production of nitrogen monoxide [1]. Schiff bases obtained from the 11Н-indeno[1,2-b]quinoxalin-2-one are highly cytotoxic and possess antiviral activity [2]. Spiro compounds with the 11Н-indeno[1,2-b]quinoxaline fragment are of practical interest. Chalcones preparation by aldol crotonic condensation of 11Н-indeno-[1,2-b]quinoxalin-2-one with acetophenones was described and their transformation into spiro compounds with cyclopropane and pyrazole rings was investigated [3, 4]. The synthetic methods for derivatives of indeno[1,2-b]quinoxaline spiro-jointed with other heterocyclic fragments are insufficiently developed.Boiling of equimolar quantities of semi(thiosemi)carbazides with compound 1 in ethanol afforded semi-(thiosemi)carbazones of 11Н-indeno[1,2-b]quinoxalin-2-one 2 and 3 in 95-97% yields. The structure and the composition of compounds 2 and 3 was proved by IR spectra and elemental analyses (Scheme 1).Semi(thiosemi)carbazones of cyclic ketones are known to by capable of heterocyclization with the formation of spiro compounds [5]. We explored the possibility to prepare new spiro compounds from semi-

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