Heteroatoms-containing tricyclic compounds
View Patent ↗A process for the production of 33-Epi-33-chloro-FR 520 in one step from FR520 wherein protecting groups are avoided.
1. A one-step process for the production of a compound of formula I
from a compound of formula ASC
said process comprising reacting the compound of formula ASC with an appropriate chlorinating agent in organic solvent, in the presence of a base, and isolating a compound of formula I obtained from the reaction mixture, wherein said process does not use protecting groups.
2. A process according to claim 1 , wherein the chlorinating agent is dichlorotriphenylphosphorane.
3. A process according to claim 1 comprising reacting FR 520 in organic solvent with a chlorinating agent in the presence of a base, wherein the chlorinating agent is provided by treating triphenylphosphine with N-chlorosuccinimide in organic solvent.
4. A process according to claim 3 , wherein the organic solvent is selected from the group consisting of aromatic hydrocarbons, ethers and nitriles.
5. A process according to claim 1 wherein the base is a pyridine.
6. A process according to claim 1 comprising reacting a compound of formula ASC with a chlorinating agent in organic solvent, wherein the chlorinating agent is provided by treating triphenylphosphine with a chlorinated alkane.
7. A process according to claim 6 , wherein a chlorinated alkane is CCl4.