Efficient one-pot preparation of bis(pyrazino[2′,3′:4,5]thieno[3,2-d]pyrimidin-4-yl)benzenes based on an aza–Wittig/mediated annulation strategy
摘要:
Aza-Wittig mediated annulation provides a highly facile and straightforward one-pot strategy for the synthesis of bis(pyrazino[2',3':4,5]thieno[3,2-d]pyrimidin-4-yl)benzenes 5 and 7. A tandem aza-Wittig reaction of iminophosphorane 2 with 1,4- or 1,3-phenylene diisocyanate, followed by intramolecular heteroconjugate addition annulation after addition of a nucleophilic reagent (amine, phenol, thiophenol or ROH), in presence of catalytic K2CO3 Or NaOR, gives selectively the functionalized bis(pyrazinothienopyrimidinones) 5 and 7. (c) 2006 Elsevier Ltd. All rights reserved.
An efficient one-pot three-step domino synthesis of substituted bis(pyrazino[2′,3′:4,5]thieno[3,2-d]pyrimidin-4(3H)-ones)
作者:Gerardo Blanco、Antonio Fernández-Mato、José M. Quintela、Carlos Peinador
DOI:10.1016/j.tet.2008.09.067
日期:2008.12
A convenient and efficient one-pot three-step domino approach to bis(pyrazinothienopyrimidinones) from ethyl 3-(triphenylphosphoranylideneamino)-thieno[2,3-b]pyrazine-6-carboxylate 1 has been developed. In this method, treatment of phosphazene 1 with a mixture of isocyanates, nitrogen, sulfur, and oxygen bis(nucleophiles) and K2CO3 in refluxing THF regioselectively furnishes the corresponding bis (pyrazino[2',3':4,5]thieno[3,2-d]pyrimid in-4(3H)-ones) in satisfactory to good yields. This methodology is highly versatile and efficient for the generation of these functionalized bis(triheterocyclic) compounds that are not readily available by other synthetic methods. (C) 2008 Elsevier Ltd. All rights reserved.
Efficient one-pot preparation of bis(pyrazino[2′,3′:4,5]thieno[3,2-d]pyrimidin-4-yl)benzenes based on an aza–Wittig/mediated annulation strategy
作者:Gerardo Blanco、José M. Quintela、Carlos Peinador
DOI:10.1016/j.tet.2006.12.049
日期:2007.2
Aza-Wittig mediated annulation provides a highly facile and straightforward one-pot strategy for the synthesis of bis(pyrazino[2',3':4,5]thieno[3,2-d]pyrimidin-4-yl)benzenes 5 and 7. A tandem aza-Wittig reaction of iminophosphorane 2 with 1,4- or 1,3-phenylene diisocyanate, followed by intramolecular heteroconjugate addition annulation after addition of a nucleophilic reagent (amine, phenol, thiophenol or ROH), in presence of catalytic K2CO3 Or NaOR, gives selectively the functionalized bis(pyrazinothienopyrimidinones) 5 and 7. (c) 2006 Elsevier Ltd. All rights reserved.