Patent ID: 9187418
Filing Date: 2015-11-17
Classification: C07B,C07C

Abstract:
1. A process for preparing (3S,3S′) 4,4′-disulfanediylbis(3-aminobutane 1-sulfonic acid) from (S) ethyl 2-(benzyloxycarbonylamino) 4-(neopentyloxysulfonyl)butanoate A comprising the steps of: (a) reducing the ethyl ester of A to give (S) neopentyl 3-(benzyloxycarbonylamino) 4-hydroxybutane 1-sulfonate B; (b) reacting the alcohol B with methanesulfonic anhydride or methanesulfonyl chloride in presence of a base to give (S) neopentyl 3-(benzyloxycarbonylamino) 4-(methylsulfonyloxy)butane 1-sulfonate C; (c) reacting the mesylated alcohol C with potassium thioacetate to give (S) 2-(benzyloxycarbonylamino) 4-(neopentyloxysulfonyl)butyl thioacetate D; (d) dimerizing D to give (3S,3S′) neopentyl 4,4′-disulfanediylbis(3-(benzyloxycarbonylamino)butane 1-sulfonate) E; and (e) deprotecting sulfonic ester and amine groups of E to give (3S,3S′) 4,4′-disulfanediylbis(3-aminobutane 1-sulfonic acid).