Process for the preparation of high purity miglustat
A process for the preparation and isolation of crystalline miglustat without the use of a column chromatography or ion exchange purification. The crystalline miglustat has a high purity and a melting point of 128° C. and an endothermic peak is 133° C.
1. A process for the preparation of crystalline miglustat of formula (I) comprising the steps of:
(1) reacting 2,3,4,6-tetra-O-benzyl-1-deoxynojirimycin hydrochloride of formula (V) with n-butyraldehyde and sodium cyanoborohydride in an organic solvent to prepare 2, 3, 4, 6-tetra-O-benzyl-N-butyl-1-deoxynojirimycin hydrochloride of formula (VI);
(2) reacting 2, 3, 4, 6-tetra-O-benzyl-N-butyl-1-deoxynojirimycin hydrochloride of formula (VI) with hydrogen in the presence of 10% Pd/C and HCl to produce miglustat hydrochloric salt;
(3) dissolving miglustat hydrochloric salt in a first solvent and adding an organic base;
(4) optionally removing the first solvent, and
(5) adding a second solvent to crystallize miglustat.
2. The process for the preparation of crystalline miglustat according to claim 1 , wherein none of the steps (1) to (5) involves the use of any flash column chromatography or ion exchange column.
3. The process for the preparation of crystalline miglustat according to claim 1 , wherein the first solvent is selected from the group consisting of water, methanol, ethanol, isopropanol, n-butanol, t-butanol, and a mixture of thereof.
4. The process for the preparation of crystalline miglustat according to claim 1 , wherein the second solvent is selected from the group consisting of dichloromethane, ethyl acetate, diethyl ether, diisopropyl ether, isopropyl acetate, hexane, cyclohexane, heptane, and a mixture thereof.
5. The process for the preparation of crystalline miglustat according to claim 1 , wherein the organic base is triethylamine, N,N-diisopropylethylamine, N-methylmorpholine, 1,8-diazabicycloundec-7-ene, or 1,5-diazabicyclonon-5-ene.
6. The process for the preparation of crystalline miglustat according to claim 1 ,
wherein the first solvent is methanol,
wherein the organic base is 1,8-diazabicycloundec-7-ene, and
wherein the second solvent is dichloromethane.
7. A process of preparing crystalline miglustat of formula (I) comprising the steps of:
treating a solution of miglustat acid salt in a first solvent with an organic base, optionally removing the first solvent, and
adding a second solvent to crystallize miglustat of formula (I),
wherein no flash column chromatography or ion exchange column is used in the process.
8. The process of preparing crystalline miglustat according to claim 7 ,
wherein the miglustat acid salt is formed from miglustat reacting with an inorganic acid or an organic acid.
9. The process of preparing crystalline miglustat according to claim 8 ,
wherein the inorganic acid is selected from a group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, and a mixture thereof, and
wherein the organic acid is selected from a group consisting of acetic acid, methanesulfonic acid, formic acid, citric acid, and a mixture thereof.
10. The process of preparing crystalline miglustat according to claim 7 ,
wherein the organic base is triethylamine, N,N-diisopropylethylamine, N-methylmorpholine, 1,8-diazabicycloundec-7-ene, or 1,5-diazabicyclonon-5-ene.
11. The process of preparing crystalline miglustat according to claim 7 ,
wherein the miglustat acid salt is miglustat hydrochloride, and
wherein the first solvent is selected from the group consisting of water, methanol, ethanol, isopropanol, n-butanol, t-butanol, and a mixture of thereof.
12. The process of preparing miglustat according to claim 7 ,
wherein the second solvent is selected from the group consisting of dichloromethane, ethyl acetate, diethyl ether, diisopropyl ether, isopropyl acetate, hexane, cyclohexane, heptane, and a mixture thereof.