A new synthesis of pyrazolo[3,4-d]pyrimidines

Abstract

The details will be reported in a separate paper.

Facile One‐Pot Synthesis and Antimycobacterial Evaluation of Pyrazolo[3,4‐d]pyrimidines

“…One disadvantage of this approach is the concomitant arylation of the pyrazole moiety. Earlier, this class of compounds was synthesized by fusion of 6-uracil hydrazones at 3008C [28]. Another synthesis reported by Maki et al [28] required the cycloaddition of an arylhydrazone to 6-chloro-5-nitrouracil, which involved several steps.…”

“…Earlier, this class of compounds was synthesized by fusion of 6-uracil hydrazones at 3008C [28]. Another synthesis reported by Maki et al [28] required the cycloaddition of an arylhydrazone to 6-chloro-5-nitrouracil, which involved several steps. Further, Kanazawa et al [29] synthesized pyrazolo [3,4-d]pyrimidines by the reaction of 6-benzylidenehydrazonouracils with N-bromosuccinimide (NBS) in acetic acid under reflux conditions, which yielded triazino-and pyridazino-uracils in addition to the pyrazolo[3,4-d]pyrimidines.…”

Studies on 6-[(Dimethylamino)methylene]aminouracils: a Facile One-pot Synthesis of Pyrimido[4,5-d]pyrimidines and Pyrido[2,3-d]pyrimidines.

“…9 The heteroannulation of uracils usually require either forcing conditions 10 or relatively longer synthetic pathways. 11 In continuation of our studies on uracil analogues 12 we now want to present a new, simple and efficient preparation of novel fused pyrimidines based on [4+2] cycloaddition reaction by exploiting the 5-6 double bond of uracil in a onepot synthesis.A new approach to the synthesis of pyrimido[4,5-d]pyrimidines reported by Wamhoff et.al. 13 is the aza-Wittigtype reaction of iminophosphoranes of 5-aminouracils with aromatic isocyanates which leads to functionalised pyrimido[4,5-d]pyrimidines.…”

“…9 The heteroannulation of uracils usually require either forcing conditions 10 or relatively longer synthetic pathways. 11 In continuation of our studies on uracil analogues 12 we now want to present a new, simple and efficient preparation of novel fused pyrimidines based on [4+2] cycloaddition reaction by exploiting the 5-6 double bond of uracil in a onepot synthesis.…”

A CONVENIENT ONE POT SYNTHESIS OF PYRIDO[2,3-d]- PYRIMIDINES AND PYRIMIDO[2,3-c]PYRIMIDINES (N5-DEAZAPETRINS)

“…The reactivity of 6-aminouracils toward electrophilic reagents has been reported (3)(4)(5). The heteroannulation of uracils usually requires either forcing conditions or relatively longer synthetic pathways (12). There have been reports for direct functionalization of 6-aminouracils using the C5-C6 double bond via different techniques (9)(10)(11).…”