Hydrochloric Acid → 1-(2-Hydroxyethyl)-3,4,5,6-tetrahydropyrimidine-2-thione

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Reaction Steps

2-(3-Aminopropylamino)ethanol (118 ml) is dissolved in 1:1 ethyl alcohol-water (340 ml) and heated to 40°-50° C. Carbon disulfide (60 ml) is added dropwise over a period of about 15 minutes. An exothermic reaction occurs after about half of the amount of carbon disulfide is added. After the addition of all the carbon disulfide, the mixture is refluxed for about 1 hour. Concentrated hydrochloric acid (8 ml) is then added, and the reaction mixture is refluxed overnight. After cooling in an ice bath, the crystalline solid which separates is filtered, washed with isopropyl alcohol and t-butyl methyl ether, and dried to give 129-4 g of 1-(2-hydroxyethyl)-3,4,5,6-tetrahydropyrimidine-2-thione, melting point 112°-114° C.

Provenance & Evidence