Purification of pleuromutilin
The present invention relates to purification methods of pleuromutilin (I) by means of crystallisation and/or recrystallisation. The process according to the present invention is carried out in the presence of i-propylacetate.
1. A method for purifying pleuromutilin
by means of crystallisation and/or recrystallisation in the presence of i-propylacetate.
2. A method according to claim 1 wherein crystallisation and/or recrystallisation is carried out in the presence of an organic anti-solvent.
3. A method according to claim 2 , wherein said anti-solvent is selected from the group consisting of heptane, hexane, and mixtures thereof.
4. A method according to claim 1 , wherein crystallisation and/or recrystallisation is carried out in the presence of a combination of i-propylacetate and an anti-solvent selected from the group consisting of:
i-propylacetate in the presence of heptane,
i-propylacetate in the presence of hexane, and
mixtures thereof.
5. A method according to claim 2 , wherein the ratio of i-propylacetate to anti-solvent is from 8 to 0.25.
6. A method according to claim 1 , comprising the step of employing seed crystals to initiate the crystallisation and/or recrystallisation.
7. A method according to claim 2 , wherein the ratio of i-propylacetate to anti-solvent is from 2 to 0.4.
8. A method according to claim 1 , wherein the method removes pleuromutilin epoxide impurity.
9. A method according to claim 1 , the method yielding pleuromutilin with a purity of ≥95%.
10. A method according to claim 1 , the method yielding pleuromutilin with a purity of ≥97%.
11. A method for purifying pleuromutilin
by means of crystallisation and recrystallisation in the presence of at least one solvent, wherein at least one of the crystallisation and the recrystallisation is in the presence of i-propyl acetate.
12. A method according to claim 11 , the method yielding pleuromutilin with a purity of ≥95%.
13. A method according to claim 11 , the method yielding pleuromutilin with a purity of ≥97%.
14. A method according to claim 11 , further comprising employing seed crystals to initiate crystallisation and/or recrystallisation.
15. A method according to claim 1 , wherein at least one of the crystallisation and recrystallisation is carried out in the presence of i-propyl acetate and heptane.
16. A method according to claim 1 , wherein at least one of the crystallisation and recrystallisation is carried out in the presence of i-propyl acetate and hexane.
17. A method for purifying pleuromutilin
by means of crystallisation and recrystallisation in the presence of at least one solvent, wherein the crystallisation and the recrystallisation is in the presence of i-propyl acetate and an organic anti-solvent,
the method yielding pleuromutilin with a purity of ≥95%.
18. A method according to claim 17 , the method yielding pleuromutilin with a purity of ≥97%.
19. A method according to claim 17 , wherein the organic anti-solvent comprises heptane.
20. A method according to claim 17 , wherein the organic anti-solvent comprises hexane.