A novel synthesis of aryl tethered imidazo[4,5-b]pyrazin-2-ones through in situ ring construction and contraction
作者:Ramendra Pratap、Abhijeet Deb Roy、Raja Roy、Vishnu Ji Ram
DOI:10.1016/j.tetlet.2006.12.021
日期:2007.2
An innovative synthesis of aryl tethered 1,3-dimethylimidazo[4,5-b]pyrazin-2-ones 4 and 6 has been delineated through base catalyzed ring transformation of 6-aryl-4-(piperidin-1-yl)-2H-pyran-2-one-3-carbonitriles 1 and methyl-5-aryl-4-methylsulfanyl-2H-pyran-2-one-3-carboxylates 5 with 7-acetyl-1,3-dimethyllumazine 2 with subsequent ring contraction of the fused pyrimidine to an imidazole ring. An additional product, methyl [6-(1,3-dimethyl-2-oxo-2,3-dihydro-]H-imidazo[4,5-b]pyrazin-5-yl)-4-thiophen2- ylpyran-2-ylidene]acetate 8b, was also isolated from the reaction of 5 and 2, as a minor constituent. (c) 2006 Elsevier Ltd. All rights reserved.
Baur, Ralph; Kleiner, Erna; Pfleiderer, Wolfgang, Liebigs Annalen der Chemie, 1984, # 11, p. 1798 - 1814
作者:Baur, Ralph、Kleiner, Erna、Pfleiderer, Wolfgang
DOI:——
日期:——
Tada, Masaru; Ito, Takayori; Ohshima, Kaoru, Journal of Heterocyclic Chemistry, 1986, vol. 23, p. 1893 - 1896
作者:Tada, Masaru、Ito, Takayori、Ohshima, Kaoru
DOI:——
日期:——
BAUR, R.;KLEINER, E.;PFLEIDERER, W., LIEBIGS ANN. CHEM., 1984, N 11, 1798-1814