Synthesis of 2-Phenyl-1,3-Oxazoles, 2-Imidazolinones, and 2-Imidazolinthiones Containing a Diterpene Fragment

Abstract

The report describes the synthesis of a series of new imidazolinones-2, imidazole-2-thiones, and 1,3-oxazoles based on the interaction of 1-bromo ketones containing a diterpene fragment with urea and thiourea. It is shown that the direction of the reaction and the yields of the products depend on the nature of the initial substrates and the conditions of the reaction. For instance, boiling bromides with ureas or thiourea in ethyl alcohol in the presence of sodium carbonate leads to nucleophilic substitution, forming diterpene-substituted ureas. Performing the same reaction in ethylene glycol at a temperature of 200–250°C in the presence of potassium hydroxide results in the formation of imidazolin-2-ones or -thiones containing the diterpene fragment at the 4-position with high yields.