PROCESS OF MAKING N,N-DIACETYL-L-CYSTINE DISODIUM SALT FROM CYSTINE AND ACETYL CHLORIDE IN METHANOL IN THE PRESENCE OF SODIUM HYDROXIDE

• Main Authors: JOSE GUILLERMO ROSA, BIJAN HARICHIAN
• Format: Patent
• Language: English
• Published: 28.02.2024

A process of making N,N′-diacetyl-L-Cystine disodium salt, the process comprising: (i) Mixing hydroxy alkane (between 0.5-100 L, preferably between 0.5-10 L, more preferably between 1-3 L, most preferably 1 L per mol of cystine) with a sodium base (4.0 molar equivalents per mole of cystine) to form a cold solution at a temperature of from 5 to 10° C.; (ii) Adding cystine (1 molar equivalent) to said cold solution and stirring, for a sufficient time, to form a basic cystine solution; (iii) Optionally, Cooling the cystine solution to 5° C.; (iv) Adding acetyl chloride (2 molar equivalents per mole of cystine) portionwise, while maintaining the temperature between 3 and 50° C., preferably between 5 and 35° C., more preferably below 10° C., most preferably 5° C., thereby resulting in a white suspension; (v) Stirring said white suspension and allowing said suspension to warm up to a room temperature of 15° C. to 50° C., preferably 20° C. to 35° C., more preferably 20° C., thereby resulting in N,N′-diacetyl-L-Cystine disodium salt product dissolved in solution and sodium chloride by-product precipitated solid in said suspension. The present description discloses an exemplary process on a small laboratory scale (500 mg cystine educt; 688 mg product; 90% yield) (page 16; example 1).