Structure–activity relationship of dihydroimidazo-, dihydropyrimido, tetrahydrodiazepino-[2, 1-b]-thiazoles, and-benzothiazoles as an acylation catalyst
…, Y Kosaki, R Sato, M Shiratori, M Shibuno, T Shishido
Abstract Cyclic isothioureas 1, 2, 3, and 4 were synthesized through a four-step procedure from the corresponding ortho-bromoanilines 10 via Pd-or Cu-catalyzed cyclization– benzothiazole formation. Nonbenzo analogues 7, 8, and 9 were synthesized by a condensation reaction of cyclic thioureas 15 and α-bromoacetophenones 14. Investigations of the acylation reactions of 1-phenylethanol with acid anhydrides in the presence of these ...