... ] triazolo [1, 5 - a] pyrimidin - 5 - one vomit; Nauseant phosphodiesterase IV inhibitor soluble in dimethylformamide, dichloromethane, methanol slightly soluble in ethyl ... ] triazolo [1,5-a]pyrimidin-5-one vomit; nauseant phosphodiesterase IV inhibitor 27277-00-5