Noxyflex,Geistlich,UK,1964
ChEBI: Noxytiolin is a member of thioureas.
400 g methyl thiourea and 2.5 g NaHCO3 are dissolved in 400 ml formaldehyde solution of 35% concentration. After having been left at ordinary temperature for 2 to 3 hours, the solution is adjusted with dilute HCl to pH 7 to 7.5. After the reaction mixture had been left overnight at 15°C some of the final product crystallized and was filtered off using a Buchner funnel. The mother liquor was concentrated by evaporation in vacuo at a bath-temperature of 30°C. The crystals obtained were again collected by filtration using a Buchner funnel and were combined with the first crystalline fraction and dried in vacuo at ordinary temperature. Yield of pure substance 400 g; melting point 84°C to 86°C.
