An α-halogenated carbonyl-component reacts with sodium hydrosulfide (NaSH) and forms a
thiol in situ. The thiol reacts directly with another carbonyl component and
ammonia to form a thiazoline. The reaction works also by using elemental sulphur, an α–substituted
ketone, another carbonyl component and ammonia; in this case, a mixture of products is formed. The formation of 3-thiazolines also occurs by using α-
thioaldehyde or α-
thioketone and ammonia. A simplified route of the Asinger-reaction was developed at Degussa. An α-halogenated carbonyl compound reacts with sodium hydrosulfide (NaSH) and forms a thiol
in situ which reacts directly with aldehydes or ketones and ammonia to 3-thiazolines. The chemical industry developed based on the Asinger-reaction multi stage processes for the production of pharmaceuticals like D-penicillamine and the
aminoacid DL-
cysteine. by the Asinger reaction ==References==