Process of production of dehydrolinalyl acetate (II)

Abstract

The present invention is related to a novel and improved process for the production of dehydrolinalyl acetate (DLA), which IUPAC name is acetic acid 1-ethynyl-1,5-dimethyl-hex-4-enyl ester, starting from dehydrolinalool (DLL), which IUPAC name is 3,7-dimethyloct-6-en-1-yn-3-ol, by acetylation.

Claims

1. A process for the production of dehydrolinalyl acetate (DLA) which is a compound of formula (I): ##STR00009## wherein the process comprises reacting dehydrolinalool (DLL) which is a compound of formula (II): ##STR00010## in a reaction solution with acetic anhydride which is a compound of formula (III): ##STR00011## at a ratio of the compound of formula (III) to the compound of formula (II) of 1.5:1 up to 5:1, wherein the process is carried out in the absence of any catalyst at normal pressure and a temperature of 100-160° C. for 2 to 20 hours to yield DLA in an amount of 70% or greater.

2. The process according to claim 1, wherein the process is carried out in the absence of solvent.

3. The process according to claim 1, wherein the process forms acetic acid as a by-product of the reaction of the compound of formula (II) and the compound of formula (III), and wherein the process further comprises a step of removing any remaining acetate anhydride and acetic acid from the reaction solution.

4. The process according to claim 1, wherein the process yields of DLA in an amount of 90% or greater.

Description

EXAMPLES

Example 1

(1) Into a 350 ml four necked round bottomed flask fitted with a thermometer and a reflux condenser 164.3 g DLL (1.06 mol) and 150 ml (1.6 mol) Ac.sub.2O were added under stirring.

(2) The yellowish reaction solution was heated to 110° C. (internal temperature). After 14 h. Afterwards the Ac.sub.2O and AcOH-mixture was distilled at 10 mbar at 90-100° C.

(3) DLA was obtained in a yield of 70%.

(4) The same reaction was repeated with an amount of 250 ml Ac.sub.2O (reaction time 5 hours) and with an amount of 500 ml Ac.sub.2O (reaction time 5 hours).

(5) DLA was obtained in a yield 90% (250 ml Ac.sub.2O) and 94.2% (500 ml Ac.sub.2O).