These common heterocyclic compound, 29823-21-0, name is Ethyl 8-Bromooctanoate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. name: Ethyl 8-Bromooctanoate
In the following preparation, absolutely no water can be tolerated in the steps up to the point where distilled water is added. 222 L of dry dimethylacetamide was charged to a dry 200 gallon glass-lined reactor. The reactor agitator was set to 100-125 rpm. Cooling was applied to the condenser and valve reactor overheads were set for distillation. 41.6 kg of dry anhydrous sodium carbonate was charged to the reactor and the reactor charging port was closed. Caution was used due to some off-gassing and a slight exothermic reaction. 77.5 kg of dry 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione was charged to the reactor. Quickly, 88 kg of dry ethyl-8-bromooctanoate was charged to the reactor. The reaction was evacuated to 22-24 inches of vacuum and the reactor temperature was raised to 65-75 C. The reactor temperature was maintained and the contents were watched for foaming. The reactor mixture was sampled and monitored for conversion by monitoring the disappearance of the bromo ester in the reaction mixture by gas chromatography. The reaction was complete (0.6% bromo ester was found) after about 7 hours. The vacuum was broken and the reactor contents were cooled to 45-50 C. The contents were centrifuged and the filtrate sent into a second 200 gallon glass-lined reactor. 119 L of ethanol (200 proof denatured with 0.5% toluene) was charged to the first 200 gallon reactor, warmed to about 45 C. The filter cake was washed with warm ethanol and the wash was charged to the reaction mixture in the second 200 gallon reactor. The agitator was started on the second 200 gallon reactor. The reactor contents were cooled to about 29 C. 120 L distilled water was slowly charged to the second reactor, with the water falling directly into the batch. The reactor contents were cooled to about 8 C. The intermediate came out of solution and was held for about 9.5 hours. The resultant slurry was centrifuged. 70 L ethanol was charged to the reactor, cooled to about 8 C., and the centrifuge cake was washed. The wet cake was unloaded into double polyethylene bags placed inside a paper lined drum. The yield was 123.5 kg of ethyl 8-(6-chloro-2H-1,3-benzoxazine-2,4(3H)-dionyl)octanoate.
The synthetic route of Ethyl 8-Bromooctanoate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Goldberg, Michael M.; US2005/54557; (2005); A1;,
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