反应详情

12 g of sodium mercaptoethansulphonate are freed in aqueous solution and under nitrogen stream in a column, as described in the example 1. The mercaptoethansulphonic acid coming out of the column in aqueous solution, under nitrogen stream and at pH=1, is gradually added with arginine, in free base form, in stoichiometrical amount dissolved in water under nitrogen stream (12.7 g), by operating at pH values of between 6 and 7. Upon the salification is completed the pH of the solution of the salt must be of between 6 and 7. The solution is then concentrated to dryness giving a residue which, upon being taken with 200 ml of absolute ethanol, under stirring and in hot condition, is converted into white crystals. The suspension is agitated at 50° C. for 30 minutes, then cooled and filtered, whereby 22.8 g of white crystalline product are obtained, with a 98% yield and a melting point of 214°-216° C.; the pH in 10% aqueous solution is 6.7 and the solubility in water is perfect.

1. concentrationThe solution is then concentrated to dryness
2. customgiving a residue which
3. stirringThe suspension is agitated at 50° C. for 30 minutes
4. temperaturecooled
5. filtrationfiltered