has specified product has specified reactant ammonia ketone aldehyde elemental sulfur carbonyl compound thiazoles ring formation reaction step thiacycle synthesis Asinger reaction 2021-12-16T09:29:30Z A multicomponent reaction (A-4CR) in which 3-thiazolines (2,5-dihydro-1,3-thiazoles) or mixtures of several 3-thiazolines are synthesized from elemental sulfur, an alpha-substitutable ketone or aldehyde, another carbonyl component and ammonia. Asinger thiazoline synthesis Asinger-4 component reaction (A-4CR) RXNO RXNO:0000688