title: Microwave-assisted four-component, one-pot condensation reaction: an efficient synthesis of annulated pyridines.
abstract: A one-pot, effective synthesis of pyridines by a modified Kröhnke procedure is described. Polysubstituted annulated pyridines were synthesized in high yields by four-component, one-pot cyclocondensation reactions of N-phenacylpyridinium bromide, aromatic aldehydes, acetophenones or cyclic ketones in the presence of ammonium acetate and acetic acid, assisted by microwave irradiation. In this procedure, cyclic ketones with two alpha-CH(2) groups yield annulated pyridines with additional alpha-benzylidene groups, which are derived in situ from double aldol condensation of cyclic ketones with two moles of aromatic aldehydes.
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China. cgyan@yzu.edu.cn
authors.forename: Chao-Guo
authors.initials: CG
authors.lastname: Yan
authors.forename: Xi-Mei
authors.initials: XM
authors.lastname: Cai
authors.forename: Qi-Fang
authors.initials: QF
authors.lastname: Wang
authors.forename: Ting-Yu
authors.initials: TY
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Zheng
mesh_terms: D018360:Crystallography, X-Ray; D008872:Microwaves; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D011725:Pyridines