The Exploration Of New Synthetic Method Of Folic Acid

Folic acid is an indispensable nutrient for human beings and has a large mark et demand.However,the current production process of folic acid has the problems of low yield,low purity and difficult disposal of waste liquid.So a new technolo gy to produce folic acid is urgently needed to meet the demand of people’s daily l ives.To solve this problem,two different processes were explored and the followin g process was selected: The intermediate 2,2,3-trichloropropanal was substituted for 1,1,3-trichloroacetone to react with N-(P-aminobenzoyl)-L-glutamic acid(ammonia A)and 2,4,5-triamino-6-hydroxy pyrimidine sulfate(ammonia B)to synthesize folic acid.This process has obviously economic and social benefit due to a wide range of raw materials,a lower energy consumption and lesser environment pollution.In the synthesis of the intermediate 2,2,3-trichloropropanal,effects of synthetic route,reflux time and vacuum distillation conditions were studied and the suitable technological conditions were determined as follows: Acrolein was reacted with chlorine gas and water under 0 ℃.Then the mixture were heated for 30 minutes at the reflow temperature and2-chloroacrylaldehyde was got.The resulting acrolein was then added with chlorine.Finally,the distillation component at 43-45°/25 mm Hg was collected.The yield of2,2,3-trichloropropanal was 79.8%.Crude folic acid was prepared with ammonia A,ammonia B and2,2,3-trichloropropanal as main materials.Effects of the feeding adding order,feeding molar ratio,p H of reactant solution and reaction time were studied and the optimum process conditions were got.The feeding adding order was that 2,2,3-trichloropropanal was dropped to the mixture of ammonia A and ammonia B;the molar ratio of ammonia A,ammonia B and 2,2,3-trichloropropanal was 1:1:1.6;the p H of reaction system was 8;reaction time was 5h;reaction temperature was 40 ℃.The product yield was 57.9%.According to the composition of the filtrate after folic acid synthesis,the feasibility of the recycling filtrate was studied.It was found that the waste water could be recycled twice.As for purification process of folic acid,the concentration of sodium citrate,reaction temperature,dosage of activated carbon and crystallization temperature on the yield and purity of folic acid were studied and the optimum process conditions were determined: the concentration of sodium citrate was 6%,the reaction temperature was 90 ℃,the dosage of activated carbon was 2.5% and the reaction time was 30 ℃.The purity of folic acid was96%.Compared with the original process,the emission of waste water was decreased.In addition,the biodegradability of sodium citrate made it easy to deal with the waste water.