Process for the esterification of a carbothioic acid
US9670246B2 · kind B2 · utility
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12Claims
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Key dates
| Filing date | Dec 2, 2004 |
| Grant date | Jun 6, 2017 |
| Priority date | — |
| Expiry date | Jan 13, 2029 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61P29/00
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A process for preparing compounds of formula [II]by esterification of the C-17 hydroxyl group of 6α,9α-difluoro-11β,17α-dihydroxy-16α-methyl-3-oxoandrosta-1,4-diene-17β-carbothioic acid, the compound of formula [I] comprises treating compound [I] with a slight excess of an acyl chloride of general formula R—COCl, where R represents —CH2CH3, —CH2CH2CH3 or —CH(CH3)2, in an inert solvent, in the presence of a tertiary amine.Preferably the process is carried out using pyridine in the presence of acetone at a temperature of from 5° C. to −20° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.