TH19890A - ??????????? 2 - ???????? - 4 - ?????????????????? ?????? (MHA) ???????????????????????? - Google Patents

Abstract

1. ??????????? 2- ????????-4- ??????????????????? ????? (MHA) ????????? ?????????????? 2.1 ???? ?????????????????????????????????????????? MHA ???????????????????????? ?????????????????????????????? MMP - ???????????? ????????????????????? - ??????? ????????????????? ????- ??????? ??????????- ??????? ??? ????????????????? ???????????????????????????????????????? 2.2 ?????????????????????????????? MHA ???????????????? ????/??????? ??????????????????????????????????????????? ?????????????????? MHA ??? ???????????????? ?????????? ???????????? ??????? ?????????????????????????????? MHA ????????????? ???????? ???????????????????????????????????????????????? ????????????? ??????????????????????????? MHA ??????????? ??????????????????????????? ?????????????????? MHA ????????????????????? ??????????? MHA ???????????? ???????????????????? ?????? ???/?????????????? ?????????????? ???????????????? 2.3 ??????????????????

Claims (16)

1. A procedure for the production of 2-hydroxy-4-methylhyobutyrid acid (MHA) by separating MHA from the reaction mixture obtained by bonding hydrogen cyanide (HCN) to methyl mercaptopropionaldehyde (MMP) and by hydroxyl hydrosis of methyl mercaptopropionaldehyde-cyanahydrin (MMP-CH) obtained with sulfuric acid, consisting of (a) concentration of the reaction mixture by evaporation under conditions to obtain anhydrous salts containing MHA; (b) further processing of the remaining salts containing MHA with an organic solvent under conditions to obtain a suspension; (c) separation of the fractional portion. Solids are removed from the suspension under normal conditions to obtain a solution containing MHA (d) Removal of the organic solvent from the solution containing MHA and recovery of the remaining MHA, and where the remaining MHA is subsequently pretreated, if necessary, by adding water. 2. The procedure under claim 1 where the reaction mixture is concentrated by evaporation to a residue of less than 5% in relation to MHA + oligomer. 3. The procedure under claim 1 in a location where the reaction mixture is completely anhydrous. 4. The procedure under claim 1 where the evaporation of the reaction mixture is carried out continuously. 5. The procedure under claim 1 in which the mixture of the preceding reaction and/or the mixture during thickening by evaporation is subjected to adianbatic evaporation cooling under a vacuum of approximately 60°C or lower to remove any volatile or pungent components of the reaction mixture. 6. The procedure under claim 1 where the evaporation of the reaction mixture is carried out after pre-neutralization with ammonia. 7. The procedure under claim 1 in which the residual salt containing the obtained MHA is a product located at the bottom of (a) and is processed with acetone, methyl isopropyl ketone, methyl isobutyl ketone, isopropanol, toluene, or tetrahydrofuran as an organic solvent in (b). 8. The procedure under claim 1 in which the suspensions formed in (b) are filtered during which crystals of ammonium sulfate salt with a purity of > 99 % are deposited as a solid portion and a solution containing MHA is deposited. 9. The procedure under claim 1 in which the solvent is separated from a solution containing MHA under conditions of re-distillation and/or acetiotropism, and the separated solvent contains less than 5% water. 10. The process pursuant to claim 1 in which the hydraulics of MMP-CH are achieved in two stages and MHA-Amid is obtained in the first stage and MHA in the second stage. 11. The procedure under claim 10 in which MMP-CH is hydrolyzed in the first step with 60-85% sulfuric acid in a molar ratio of 1:1.0 at temperatures between 20°C and 60°C. 12. The process under claim 11 in which the resulting mixture in the first hydraulic step is free of non-reactive cyanolin. 13. The process pursuant to claim 10 where MHA amid is hydrolyzed in a second step by adding water and additional sulfuric acid to the stoichiometric limit at a temperature of 90°C - 110°C or under reflux conditions. 14. A procedure for the production of 2-hydroxy-4-methylthiobutyric acid (MHA) is performed, separating MHA from the reaction mixture obtained by adding hydrogen cyanide (HCN) to methylmercaptopropioandehyde (MMP) and by hydraulic lysis of methylmercaptopropioandehyde cyanahydrin (MMP-CH) obtained with sulfuric acid. The separated MHA from the reaction mixture consists of a solid/liquid separation carried out with either the remaining gelatinous salt or the remaining salt containing the solid MHA using an organic solvent. 15. The procedure under claim 8 in which the solid ammonium sulfate salt is selectively induced after the pre-evaporation of the remaining solvent and made into a concentrated mixture with water and introduced into a system in contact with sulfuric acid for the recovery of sulfuric acid. 16. The procedure under claim 1 or 8 where the evaporation of the reaction mixture is carried out without pre- or after pre-evaporation with ammonia and the ammonium bisulfate salt obtained in solid form and induced, possibly selected after pre-evaporation of the remaining solvent and made into a concentrated mixture with water and introduced into a system in contact with sulfuric acid where sulfuric acid is recovered.