Synthesis of new pyrrolo[3,4-b]- and [3,4-c]pyridin(on)es and related 1,7-naphthyridinones and 2,7-naphthyridines via intramolecular Diels-Alder reactions of 2(1H)-pyrazinones
摘要:
2(1H)-pyrazinones 7, 10 or 12 with in 6-position a 2-propynylaminomethyl or 3-butynylaminomethyl side chain undergo intramolecular Diels-Alder reactions providing cycloadducts which can he isolated or functionalised in some cases. By further thermolysis of these compounds either pyrrolo-[3,4-b]pyridinones 15/16 and/or pyrrolo[3,4-c]pyridines 17/18 or 1.7-naphthyridinones 25 and/or 2,7-naphthyridines 26 can be generated. Loss of either cyanide or isocyanate from the respective adducts is shown to be dependent on their substitution pattern. Copyright (C) 1996 Elsevier Science Ltd
Generation of 6-alkylidene/benzylidene-3,6-dihydropyrazin-2(1H)ones by reaction of 6-bromomethylpyrazin-2(1H)-ones with methoxide and further conversion into specific piperazine-2,5-diones and pyrazin-2(1H)-ones
Expanding the substitution pattern of 2(1H)-pyrazinones via Suzuki and Heck reactions
作者:Rasha Azzam、Wim M. De Borggraeve、Frans Compernolle、Georges J. Hoornaert
DOI:10.1016/j.tet.2005.02.056
日期:2005.4
Various 3,5-dichloropyrazinones were substituted at the C-3 position with (hetero)aryl, alkyl and alkenyl groups by means of Suzuki and Heck reactions. The methodology could be extended to reactions on the far less reactive C-5 position by transhalogenation of the 5-Cl substituent to a 5-Br or a 5-I group prior to performing the cross-coupling. (c) 2005 Elsevier Ltd. All rights reserved.