Lamivudine oxalate and preparation method thereof
View Patent ↗Lamivudine oxalate, preparation method and crystalline forms thereof are disclosed. A preparation method of Lamivudine is also disclosed.
1. A Lamivudine oxalate, characterized in that the Lamivudine oxalate has the following structural formula:
2. The Lamivudine oxalate of claim 1 , wherein the Lamivudine oxalate is a crystalline Lamivudine oxalate.
3. The Lamivudine oxalate of claim 2 , wherein X-ray powder diffraction peak spectrum of the crystalline Lamivudine oxalate using Cu—Kα radiation is expressed in degree 2 θ at 21.04, 22.44, 23.46, 23.78, and 25.26.
4. The Lamivudine oxalate of claim 3 , wherein X-ray powder diffraction peak spectrum of the crystalline Lamivudine oxalate is expressed in degree 2 θ at 13.94, 14.86, 21.04, 21.30, 22.44, 23.46, 23.78, 25.26, and 33.36.
5. The Lamivudine oxalate of claim 3 , wherein endothermic transition peak of the crystalline Lamivudine oxalate measured by DSC is at about 201.9° C. and a starting transition temperature thereof is about 199° C.
6. The crystalline Lamivudine oxalate of claim 4 , characterized in that endothermic transition peak measured by DSC is at about 201.9° C. and a starting transition temperature is about 199° C.
7. A method for producing Lamivudine, comprising the steps of:
(a) adding ethanol to the Lamivudine oxalate of claim 1 to produce a first mixture;
(b) adding triethylamine to the first mixture from step (a) to produce a second mixture;
(c) stirring the second mixture;
(d) centrifuging the second mixture; and
(e) vacuum-drying the product from step (d) to produce Lamivudine crystal.
8. The method of claim 7 , wherein step (b) is performed at 40-45° C. for 0.5 hour.
9. The method of claim 7 , wherein step (c) is performed at 40-45° C. for about 4 hours.
10. The method of claim 7 , wherein step (d) is performed at room temperature.
11. The method of claim 7 , wherein step (e) is performed at 40-45° C.