Acetone cyanhydrin

Acetone cyanhydrin (a-Hydroxy sobutyronitrile) By this method, the nitrile of an a-hydroxy acid U necessarily obtained. 

ACH (1) [Acetone cyanhydrin] A process for making methyl methacrylate via this intermediate. Acetone reacts with hydrogen cyanide to yield the cyanhydrin. This is then converted to methacrylamide, using concentrated sulfuric acid. Methanolysis of this yields methyl methacrylate. Developed by Rohm GmbH Chemische Fabrik, Germany, and ICI, UK used in 11 countries in 1990. 

Method E (using acetone cyanhydrin) TBA-CN or TBA-OH (11 mmol) in MeCN (10 ml) is added dropwise over 20-30 min to the haloalkane (10 mmol) and Me2C(OH)CN (1.3 g, 15 mmol) in MeCN (20 ml) and the mixture is stirred until TLC analysis indicates the reaction to be complete. The mixture is evaporated and the residue taken up in H20 (10 ml) and Et20 (40 ml). The organic phase is separated, washed with H20 (3x5 ml), dried (MgS04), and evaporated to yield the nitrile. 

Acetone cyanhydrin has been used as a convenient source of cyanide ion for the preparation of alkyl cyanides (6.1.1.E) [21]. Moderate yields (50-77%) have been achieved using tetra-n-butylammonium cyanide or hydroxide as the base. 

Initial preparative work with oxynitrilases in neutral aqueous solution [517, 518] was hampered by the fact that under these reaction conditions the enzymatic addition has to compete with a spontaneous chemical reaction which limits enantioselectivity. Major improvements in optical purity of cyanohydrins were achieved by conducting the addition under acidic conditions to suppress the uncatalyzed side reaction [519], or by switching to a water immiscible organic solvent as the reaction medium [520], preferably diisopropyl ether. For the latter case, the enzymes are readily immobilized by physical adsorption onto cellulose. A continuous process has been developed for chiral cyanohydrin synthesis using an enzyme membrane reactor [61]. Acetone cyanhydrin can replace the highly toxic hydrocyanic acid as the cyanide source [521], Inexpensive defatted almond meal has been found to be a convenient substitute for the purified (R)-oxynitrilase without sacrificing enantioselectivity [522-524], Similarly, lyophilized and powered Sorghum bicolor shoots have been successfully tested as an alternative source for the purified (S)-oxynitrilase [525],... 

Acetic Acid Acetic anhydride Acetoacetanilide Acetone cyanhydrin Acetyl chloride Acrolein Acrylonitrile Alcohols Alkaloids... 

Conversion of byproducts in more valuable chemicals is profitable. For example acetonitrile can be converted to acrylonitrile by oxidative methyla-tion with CH4, while HCN in acetone cyanhydrine, methacrylic acid, methionine, etc. 

Similar syntheses of arylated 1,3-dioxo-cyclohexanone derivatives also lead to arylated phenols. The enolic methoxyl group of the enolketone is removed using lithiumaluminiumhydride. Acetone cyanhydrin transforms the enolic methoxyl group into a cyano group. Arylated cyano phenols are also available109) by this route ... 

Acetone, acetonyl-. See 2,5-Hexanedione Acetone chloroform. See Chlorobutanol hemihydrate Chlorobutanol Acetone cyanhydrin Acetone cyanohydrin. See 2-Hydroxy-2-methylpropanenitrile Acetonedicarboxylic acid Acetone-1,3-dicarboxylic acid. See P-Ketoglutaric acid Acetone dimethyl acetal. See Dimethoxypropane Acetone/diphenylamine condensate Acetone/diphenylamine condensates. See Di phenylam i ne-acetone Acetone/formaldehyde condensate CAS 25619-09-4 Uses In food-pkg. adhesives Regulatory FDA 21CFR 175.105... 

Synonyms Acetone cyanhydrin Acetone cyanohydrin a-Hydroxyisobutyronitrile 2-Hydroxy-2-methylpropionitrile Lactonitrile, 2-methyl-... 

Methyl methacrylate (methyl 2-methylpropenoate) is still manufactured by the old acetone cyanhydrin route ... 

The most common procedure for the technical synthesis of the monomer methyl methacrylate (MMA) is the reaction of acetone cyanhydrine with water and methanol in the presence of concentrated sulfuric acid [11] ... 

Commercial production [462] of methacrylates began in 1933 from acetone cyanhydrine, and this is still the basis for essentially all current commercial methacrylate production. The basic materials - acetone, hydrogen eyanide, and sulfuric acid - are available. In the first step, which needs anhydrous materials and conditions, methacrylamide sulfate is formed. The presence of water would form a-hydroxyisobutyramide as the main product. In the second step, methacrylamide sulfate is hydrolyzed by an excess of water to give methacrylic acid. 

The approved way of preparing the cyanohydrine 299 by the addition of prussic acid is no problem in the case of 3-phenoxybenzaldehyde 280, The use of acetone cyanhydrine as a source of prussic acid [629] seems to be advantageous. In order to circumvent the aldehyde 280, an alternative route from the trimethyl-3-phenoxy benzylammonium salt 296 and the corresponding 3-phenoxybenzyl nitrile 297 [630] was proposed, in which oxalic ester condensation and subsequent brominative degradation of this whole group was applied (Reaction scheme 211). This procedure supposedly yields a particularly pure a-bromobenzyl cyanide 298 [631]. 

Acetone cyanhydrin and aluminium chloride may be used in place of hydrogen cyanide in the Gattermann formylation of aromatic compounds. Yields and substrate reactivities are comparable to those observed with the Gattermann procedure. The trimethylstannyl groups in stannyl-pyridines and -quinolines may be replaced regiospecifically by acyl groups by reaction with acyl chlorides. When the tin substituent is not at the 2-position, palladium catalysis is necessary, but this also leads to a small amount of formation of a bipyridyl [equation (10)1. 

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