Preparation of αα-Dimethyl-4-(1-oxo-4-Chlorobuthyl)phenyl ethanol
Publication Date: 2005-Jan-26
The IP.com Prior Art Database
Preparation of α,α-Dimethyl-4-(1-oxo-4-Chlorobuthyl)phenyl ethanol
α,α-Dimethyl -4-(1-oxo-4-cyclopropane)phenyl ethanol is prepared according to US5,578,610 by hydrolysis of the acetate group in α,α-Dimethyl-4-(1-oxo-4- Chlorobuthyl)phenyl ethyl acetate underbasic conditions.
Hydrolysis of the acetate group in acidic conditions also leads to α,α-Dimethyl -4-(1- oxo-4-Chlorobuthyl)phenyl ethanol without affecting the chlorobutyl side chain.
This process comprises: dissolving α,α-Dimethyl -4-(1-oxo-4-Chlorobuthyl)phenyl ethyl acetate in an organic solvent, cooling the solution to a low temperature and adding an inorganic acid. After maintaining the solution for a period of time, preferably for about 4 hours, the phases are separated, and the organic solvent is removed to give the desired product.
Typically, inorganic acids include hydrochloric acid, phosphoric acid or sulfuric acid. Preferably, the organic solvent is MTBE or toluene.
The solution is preferably cooled to a temperature of about -10oC to about room temperature, more preferably, to a temperature of about -10oC.
Scheme I: Hydrolysis of the acetate
Example 1: α,α-Dimethyl -4-(1-oxo-4- Chlorobuthyl)phenyl ethyl acetate (10gr) is dissolved in MTBE and cooled to low temperature (-10oC). Few drops of concentrated hydrochloric or sulfuric acid are added. After 4hr. the organic phase...