Hydrochloric Acid → Carbonic acid, compound with phenylguanidine (1:1)

Participants

Reaction Conditions

Reaction Steps

88.5 g (0.78 mol) aqueous HCl (32% by weight) are added to 93.1 g aniline (1.0 mol) until the pH value reaches 2.0. Over the course of 1 hour, 92.4 g (1.1 mol) of a 50% aqueous cyanamide solution are run into the reaction mixture at 85° C. Towards the end of the cyanamide addition, a further 22.1 g (0.19 mol) aqueous HCl (32%) are added, which returns the pH to 2.4 to 2.7. After stirring for 2 hours at 85° C., the mixture is allowed to cool to 60° C. and a solution of 63.6 g (0.6 mol) sodium carbonate in 170 ml water is added over a 30 minute period. The crystalline precipitate is filtered after cooling to 5° C. 163 g phenylguanidine carbonate are produced, containing 76.7% phenylguanidine free base, which corresponds to a 92.7% yield based on aniline. The melting point (decomposition) is 147° to 150° C.

Provenance & Evidence