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US 4,379,093 AGranted
Process for preparing high purity ursodeoxycholic acid
AssigneeErregierre S.p.A.
InventorsAntonio Bonaldi, Egidio Molinari
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AssigneeErregierre S.p.A.
InventorsAntonio Bonaldi, Egidio Molinari
Estimating the term…
A process for preparing very pure ursodeoxycholic acid starting from cholic acid (I) by: (a) selectively oxidizing it to 3 alpha, 12 alpha-dihydroxy-7-ketocholanic acid (II) (b) reducing acid (II) to 3 alpha, 7 beta, 12 alpha-trihydroxy-cholanic acid (III) (c) oxidizing a 3,7-ester of acid (III) to 3 alpha, 7 beta-dihydroxy-12-keto-5-beta-cholanic acid (IV) by treatment with hypochlorite followed by hydrolysis (d) preparing the tris-trimethylsilyl derivative of acid (IV) (e) eliminating the trimethylsilyl groups (f) reducing the very pure acid (IV) by the Wolff-Kishner method to ursodeoxycholic acid. Alternatively, the Wolff-Kishner method can be applied directly to the tris-trimethylsilyl derivative, and the trimethylsilyl groups can be eliminated from the final product.
A process for preparing high purity ursodeoxycholic acid ##STR9## characterised in that a compound of formula ##STR10## in which R.sub.1 =H or a --Si(CH.sub.3).sub.3 group, is reduced with hydrazine hydrate in the presence of an alkaline base and triethylene glycol, and the product obtained, if R.sub.1 =--Si(CH.sub.3).sub.3 is subjected to acid hydrolysis.
Dependencies are inferred from the claim text.