Russian Chemical Bulletin, International Edition, Vol. 59, No. 5, pp. 1063—1064, May, 2010 1063 Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1038—1039, May, 2010. 1066-5285/10/5905-1063 © 2010 Springer Science+Business Media, Inc. The first synthesis of tetrahydrobenzo[b]pyrrolo[2,1-f][1,6]naphthyridine by the Michael addition of butyn-2-one to 1-(2-methoxycarbonylvinyl)tetrahydrobenzo[b][1,6]naphthyridine L. G. Voskressensky, I. V. Vorobiev, Т. N. Borisova, L. N. Kulikova, А. V. Bolshov, and А. V. Varlamov The Russian Peoples Friendship University, 6 ul. Miklukho-Maklaya, 117198 Moscow, Russian Federation. Fax: +7 (495) 955 0779. E-mail: lvoskressensky@sci.pfu.edu.ru The reaction of 10-cyanotetrahydrobenzo[b][1,6] naphthyridines with activated alkynes results in a mixture of 1-methoxycarbonyl- or 1,2-dimethoxycarbonylvinyl- substituted tetrahydrobenzonaphthyridines 1 and am- monium ylides derived from tetrahydrobenzo[b]pyrrolo- [2,1-f][1,6]naphthyridine 2. 1 The formation of the latter is caused by the Stevens rearrangement or by attack of the anionic center on the ester group in the intermediate ylide (Scheme 1). It was of interest to prepare 1,1-di(vinyl)-substituted benzonaphthyridines using the reaction of compounds 1 with activated alkynes and to carry out the synthesis of Scheme 1 Scheme 2 R = Me, Pr i ; R´ = H, Br, F, NO 2 ; X = H, CO 2 Me