Patent ID: 9670246
Date: 2017-06-06
CPC Classifications: A61P,C07J

Claim:
1. A process for preparing fluticasone propionate comprising: (i) esterification of the C-17 hydroxyl group of 6α,9α-difluoro-11β, (ii) wherein esterification comprises contacting compound [I] with from 1.0 mol to 1.2 moles of an acyl chloride of general formula R—COCl per mol of compound [I], in an inert solvent, in the presence of a tertiary amine at a temperature of from 5° C. to 0° C., where R represents —CH and (iii) converting compound [II] to fluticasone propionate wherein the fluticasone propionate contains less than 0.3% dimer G