Sodium Hydroxide → HCID 178460306, compound

To a solution of 113.2 g. of propoxyamine hydrochloride in 200 ml. of ice cold water there is added 81.2 g. of 50% aqueous sodium hydroxide solution. The mixture is stirred for thirty minutes and 141.0 g. of S-methyl-2-thiopseudourea sulfate and 200 ml. of water are added. The mixture is stirred at room temperature for two hours and then heated to reflux for one hour. The mixture is treated with 81.2 g. of 50% aqueous sodium hydroxide filtered and evaporated in vacuo. The residue is slurried in 200 ml. of absolute ethanol, the suspension filtered and the filtrate evaporated to an oil. The crude oil is dissolved in 300 ml. of chloroform, the mixture is cooled and filtered to give a clear solution of the guanidine free base. The chloroform solution is made acidic with methanolic hydrogen chloride and then evaporated in vacuo to give propoxyguanidine hydrochloride as a clear viscous oil (m.p. of picrate 179°-80° C).