1-Chloro-6,6-dimethyl-2-heptene-4-yne synthesis

Yield:-

Reaction Conditions:

with hydrogenchloride;trichlorophosphate in water;acetonitrile at 10 - 28; for 6.33333 h;

Steps:

2
30 kg of pure 6,6-dimethyl-1-heptene-4-yne-3-ol obtained in Example 1 was taken into a reactor containing 103 liters of acetonitrile under stirring. The mass was cooled to 10 °C and a homogeneous mixture of 7.1 liters of phosphorous oxychloride in 52 liters of aqueous hydrochloric acid was added to the mass slowly at 12 ⁰C. The mass was maintained at this same temperature for 60 minutes and then the temperature was raised to 25 °C. Temperature was maintained at 28 ⁰C for 5 hours and then 130 liters of water was charged. The mass was stirred for 20 minutes and was extracted three times with petroleum ether (3*90 liters). The combined organic layers were washed with water (4*100 liters) and the solvent was distilled completely below 80 °C to get 42.8 kg of the title compound as a residue.The residue thus obtained was charged into a clean and dry reactor and was purified by fractional distillation. The main fraction was collected at 57-98 °C under reduced pressure of 30-60 torr to get 22.2 kg of the purified 1-chloro-6,6- dimethyl-2-heptene-4-yne.

References:

DR. REDDY'S LABORATORIES LTD.;DR. REDDY'S LABORATORIES, INC. WO2007/44273, 2007, A1 Location in patent:Page/Page column 16

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