

2-SUBSTITUTED [1]BENZOPYRANO[4,3-d]PYRIMIDIN-5-ONES
Abstract
A new method is reported for the synthesis of 2-R-substituted [1]benzopyrano[4,3-d]pyrimidin-5-ones (R = p-phenyl, p-chlorophenyl-, p-carbamoylphenyl-, 3-pyridinyl-, 4-pyridinyl-, 2-pyrazinyl-, pyrrolidino-, morpholino-, 3,6-dimethyl-1-pyrazolyl-) by the reaction of 4-chloro-3-formylcoumarin with salts of the corresponding amidines RC(=NH)NH2HX in DMF in the presence of piperidine or triethylamine. 3-Formyl-4-coumarin and 2-aminobenzimidazole give [1]benzopyrano[2,4:3',4']-pyrimido[1,2-a]-benzimidazol-6-one, whose structure was demonstrated by X-ray diffraction structural analysis.
How to Cite
Strakova, I.; Petrova, M.; Belyakov, S.; Strakovs, A. Chem. Heterocycl. Compd. 2007, 43, 793. [Khim. Geterotsikl. Soedin. 2007, 935.]
For this article in the English edition see DOI 10.1007/s10593-007-0128-4
Keywords
2-substituted [1]benzopyrano[4,3-d]pyrimidin-5-ones; benzene and heterocyclic C- and N-carbamidines; 4-chloro-3-formylcoumarins
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv