N,N-Dimethylglycine hydrochloride synthesis

Yield:-

Reaction Conditions:

Stage #1:dimethyl amine;chloroacetic acid in water at 25 - 55; for 11 h;
Stage #2: with hydrogenchloride in water at 40;

Steps:

According to the present invention, in the step a, 100 kg of chloroacetic acid are added to 63 kg of water for forming the solution A.In the step b, the solution A is dropped to 600 liters of liquid dimethylamine to form solution B.In the step c, the solution B is stirred at a temperature less than 25 degree C., afterwards, the stirred solution B is kept at a temperature less than 30 degree C. for the dropping process, and keep stirring for at least 1 hour, finally, the solution is heated to 50-55 degree C. and kept 10 hours.In the step d, the solution obtained from the step c is decompressed and heated for eliminating ammonia and water, while the decompression process is stopped at 90 degree C. to make sure the pH Value of the solution is in a range within 6.5-7.0;In the step e, 158 liters of hydrochloric acid are dropped to the solution formed from step d) at a temperature less than 40 degree C. to form a solution C, afterwards, the solution C is further decompressed to eliminated water, while the decompression process is stopped at 98-100 degree C., finally, the decompressed solution C is collected for testing concentration.In the step f, the decompressed solution C is centrifugalized at a temperature less than 30 degree C. to obtain a semifinished product, and after the semifinished product is weighted, the parent liquid is concentrated again.In the step g, 130-160 kg of the semifinished product from step f are added to the same weight of deionized water and heated till dissolved completely to form solution D.In the step h, active carbon (6% of semofinished product weight) is added to the solution D to form a mixture, and then, the mixture is stirred and keep temperature for half hour, afterwards, the mixture is filtered.In the step i, the filterate is cooled and centrifugalized at a temperature below 30 degree C. to obtain the fine product of N,N-Dimethyl Glycine hydrochloride, finally, the parent liquid is concentrated and crystallized continually.Property of the N,N-Dimethyl Glycine Hydrochloride Made by the Above Producing Method According to the First Preferred Embodiment of the Present Invention. MOLECULAR FORMULA C4H10NO2CL MOLECULAR WEIGHT 139.58 APPEARANCE White crystals MELT POINT 188-198 degree C. WATER CONTENT <2% RESIDUE ON IGNITION <1% HCI CONTENT 25.5-27.0% DMG CONTENT 98.0-102.0%

References:

Zhang, Jiashu US6875890, 2005, B1 Location in patent:Page/Page column 3

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