Synthesis of novel fused chromone–pyrimidine hybrids and 2,4,5-trisubstituted pyrimidine derivatives via ANRORC rearrangement
作者:M. Sambaiah、K. Raghavulu、K. Shiva Kumar、Satyanarayana Yennam、Manoranjan Behera
DOI:10.1039/c7nj01839h
日期:——
A facile and versatile procedure for the synthesis of functionalized novel 2, 5-diphenyl-5H-chromeno [4, 3-d] pyrimidin-5-ol and (2, 4-diphenylpyrimidin-5-yl) (2-hydroxyphenyl) methanone has been described. The key step in the synthesis involves the ANRORC reaction of 3-benzoyl chromones with benzamidines.
Novel conversion of 3-(α-hydroxybenzyl)flavones to 3-benzoylchromones and 3-cyanoflavones with NaN3/TFA
作者:Asok K Mallik、Falguni Chattopadhyay、Sankar P Dey
DOI:10.1016/s0040-4039(00)00730-9
日期:2000.6
On treatment with NaN3/TFA, 3-(α-hydroxybenzyl)flavones are converted to 3-benzoyl- chromones and 3-cyanoflavones, plausible mechanisms for which have been suggested.
The bioinspired design of a reagent allows the functionalization of C<sub>α</sub>–H of α,β-unsaturated carbonyl compounds via the Baylis–Hillman chemistry under ambient conditions
A rationally designed reagent capable to affect alkylation at C[small alpha] of [small alpha], [small beta]-unsaturated carbonylcompounds is reported. The reaction proceeded at room temperature without any additives. The pH and H-Bond...
The directed lithiation of some 3-acylchromone acetals
作者:G.Elena Daia、Christopher D. Gabbutt、John D. Hepworth、B.Mark Heron、David E. Hibbs、Michael B. Hursthouse
DOI:10.1016/s0040-4039(97)10733-x
日期:1998.3
3-Acylchromone acetals are lithiated at C-2. Subsequent electrophilic trapping gives chromones 4 together with a ring-contracted dimer 6. During the formation of someacetals, an acid-catalysed rearrangement to a 2-substituted 3-formylchromone acetal is observed.
Reactions of 3-acylchromones with dimethyl 1,3-acetonedicarboxylate and 1,3-diphenylacetone: one-pot synthesis of functionalized 2-hydroxybenzophenones, 6H-benzo[c]chromenes and benzo[c]coumarins
作者:Viktor O. Iaroshenko、Iryna Savych、Alexander Villinger、Vyacheslav Ya. Sosnovskikh、Peter Langer
DOI:10.1039/c2ob07020k
日期:——
Reactions of 3-methoxalyl-, 3-polyfluoroacyl- and 3-aroylchromones with dimethyl 1,3-acetonedicarboxylate and 1,3-diphenylacetone in the presence of DBU proceed at the C-2 atom of the chromone system with pyrone ring-opening and subsequent formal [3 + 3] cyclocondensation to functionalized 2-hydroxybenzophenones, 6H-benzo[c]chromenes and benzo[c]coumarins, depending on the substituent at the 3-position. An NMR study and X-ray crystallographic analysis are reported. The compounds synthesized can be considered as promising scaffolds for the design of the novel UV-A/B and UV-B filters.