4-Aryl-5-(pyrimidin-2?-yl)-1,4-dihydropyridines,-1,4-di- and -1,2,3,4-tetrahydropyrimidines

Benzoxazolyl-and benzothiazolyl-guanidines in three-component reactions

“…For example, interaction of aromatic aldehydes, (thio)urea, and β-diketones in Biginelli conditions gave dihydro(thia)pyrimidones, which are calcium channel activators, antagonists of adrenoreceptors, etc. [2][3][4].At present there are no reports connected to the use in such reactions of guanidines, despite the great synthetic potential of the latter [5].In this work the three component condensation of benzoxa(thia)zolyl-2-guanidines 1a,b with orthoesters (RC)OEt 3 2a,b (a R = H, b R = Me) and active methylene compounds containing a carbonyl function has been studied. In this case one can expect formation of products of linear combination [6] and products of subsequent cyclization.…”

“…For example, interaction of aromatic aldehydes, (thio)urea, and β-diketones in Biginelli conditions gave dihydro(thia)pyrimidones, which are calcium channel activators, antagonists of adrenoreceptors, etc. [2][3][4].…”