Synthesis of Pyrimidines with Ammonium Acetate as Nitrogen Source Under Solvent‐Free Conditions

Abstract

A three-component tandem reaction for the synthesis of multisubstituted pyrimidines from chalcone, benzyl alcohol and NH 4 OAc have been developed. This transformation represents an example for the simultaneous formation of two new C(sp 2 )À N bonds and a six-membered ring using NH 4 OAc as nitrogen source under solvent-free conditions.

One-Pot Synthesis of 1,5-Diketones under a Transition-Metal-Free Condition: Application in the Synthesis of 2,4,6-Triaryl Pyridine Derivatives

“…Functionalized pyridines are among the most common heterocyclic compounds that have been used in therapeutic drugs, , chemosensors, photosensitizers, as ligands for catalysis, and as starting materials in the synthesis of agricultural chemicals such as insecticides, herbicides, and surfactants . Thus, several synthetic methods have been established to produce 2,4,6-triaryl pyridine derivatives. − The most common approach for the synthesis of substituted pyridine is ammonium acetate (NH 4 OAc)-mediated cyclization of 1,5-diketones. ,− Accordingly, the treatment of 1,5-diketones 3 and 4 with NH 4 OAc as a nitrogen source successfully produced good yields of the reported pyridine-based molecules 5a–e ,,, within a moderate reaction time under a catalyst-free system (Table ). Our finding reveals that 1,5-diones with weak electron-donating groups, such as methyl and chloro groups, on the aromatic ring could provide relatively higher yields of the corresponding 2,4,6-triaryl-substituted pyridines ( 5a–d ) than those substrates with strong electron-donating groups, such as the methoxy group ( 5e ).…”

Direct Synthesis of 2,4,6‐Trisubstituted Pyrimidines via Base‐Mediated One‐Pot Multicomponent Reaction

“…In 2019, Chen et al. used ammonium acetate as a nitrogen source to produce pyrimidine heterocyclic rings from chalcone and benzyl alcohol using tandem multicomponent reaction under the catalysis of Cu(OTf) 2 (Scheme 1, (4)) [18] . Despite these advanced developments, more economical and convenient methods that can synthesize substituted pyrimidines should still be developed.…”