Abstract: The reaction time and ease of handling of reactants in the known process of forming optically active (S)-cyanohydrins by reacting aldehydes with hydrocyanic acid in the presence of the enzyme S-oxynitrilase and a solvent may be significantly improved over the known methods when the solution of aldehydes and acid is passed through a porous membrane comprising a polymeric resinous binder having finely divided filler particles dispersed throughout the binder to which the S-oxynitrilase enzyme has been chemically bound.

Abstract: Alpha-aminonitriles can be synthesized by the reaction, at ambient temperature without use of catalyst, of essentially stoichiometric amounts of amine, aldehyde (either monoaldehyde or dialdehyde) and trimethylsilyl cyanide.

Abstract: A process for the purification of crude cyanohydrins which contain 3 to 6 carbon atoms, especially of crude acetone cyanohydrin, by distilling off the unreacted reactants namely hydrogen cyanide and the carbonyl compound. The purification becomes very simple, and the unreacted reactants can be fed directly into the cyanohydrin synthesis, when the vacuum is generated with a liquid jet pump. The exhaust vapors arising in the distillation or desorption are led into the driving jet of the pump, the liquid jet pump is driven with crude cyanohydrin which contains basic catalyst, and the exhaust vapors absorbed in the crude cyanohydrin are reacted to completion in a cooled reaction circuit in which the liquid jet pump is incorporated.

Abstract: A novel process for effectively preparing an optically active cyanohydrin comprising asymmetrically cyanating an aldehyde by reacting the aldehyde with a cyanating agent in the presence of a titanate of an optically active tartaric acid derivative.

Abstract: 1-Cyano-1-(4-alkylphenyl)alkenes having utility as chemical intermediates, especially in the preparation of ibuprofen and related pharmaceuticals, are prepared by reacting an alkylbenzene with an alkali metal cyanide and an acid halide in the presence of aluminum chloride.

Abstract: Hydrogen cyanide addition to a monosaccharide results in a mixture of product cyanohydrins whose ratio can be changed by conducting the hydrogen cyanide addition in the presence of an agent which forms a complex with the monosaccharide. It is preferred to add the elements of hydrogen cyanide to a preformed complex of the monosaccharide. The product selectivity appears to be dependent upon the concentration of the complexing agent up to about one molar proportion of the latter relative to the monosaccharide with the selectivity being invariant thereafter.

Abstract: A method of homologating monosaccharides via their cyanohydrins utilizes transcyanohydrination across a phase boundary from a water-insoluble donor cyanohydrin dissolved in an organic, water-immiscible solvent to an aqueous solution of a receptor monosaccharide. This heterogeneous transcyanohydrination can be incorporated into a cyclic process where the cyanide donor is enzymatically regenerated via enzyme catalyed addition of HCN to a suitable aldehyde. The latter process can be made continous or semicontinuous by immobilization of the enzyme.

Abstract: The present invention relates to a novel process for the preparation of insecticidally active esters of the general formula (I) ##STR1## wherein R.sub.1 and R.sub.2 are the same or diferent from each other and represent a hydrogen or a halogen atom; R.sub.3 represents ##STR2## (wherein R.sub.4 and R.sub.5 represent a chlorine or bromine atom or a methyl group when R.sub.4 is identical to R.sub.5, but R.sub.4 represents a chlorine or bromine atom or a methyl group and R.sub.5 represents a trifluoromethyl group when R.sub.4 is different from R.sub.5, and R.sub.6 represents a halogen atom or a difluoromethoxy group); and R.sub.8 represents a hydrogen or a cyano group.The characteristic of the present invention is a one-step procedure comprising directly condensing an organic acid, an aldehyde (and a water-soluble cyanide) in the presence of a phase transfer catalyst and a water-soluble inorganic base by the use of a sulphonyl compound as a condensing reagent.

Abstract: Optically active cyanohydrins are produced by the reaction of an aldehyde with hydrocyanic acid in the presence of D-oxynitrilase (E.C.4.1.2.10). The reaction takes place in an organic solvent which is not miscible with water, but which is saturated with water or an aqueous buffer solution.

Abstract: A process for the preparation of .alpha.-cyanobenzyl esters of cyclopropane carboxylic acids and substituted alkanoic acids by treating a carboxylic acid and a benzaldehyde with a metal cyanide, followed by treatment with a sulfonyl halide.

Abstract: A process for the preparation of a dimeric aromatic acyl cyanide of the formula ##STR1## in which Ar is optionally substituted phenyl, naphthyl or hetaryl,comprising reaction an acyl halide of the formulaAr--CO--Halin whichHal is fluorine, chlorine or bromine, with an alkali metal cyanide in a two-phase system comprising water and a water-immiscible or only sparingly water-miscible aliphatic ketone, and in the presence of a phase-transfer catalyst. The products are known intermediates for pesticides.

Abstract: Reaction products of hydrogen cyanide are prepared by a process in which hydrogen cyanide prepared in a conventional manner by pyrolysis at from 250.degree. to 650.degree. C. over a solid under from 5 to 200 mbar is cooled to a temperature of from 200.degree. to -10.degree. C. together with the other pyrolysis products, the hydrogen cyanide is then fed to a chemisorption reaction with a base or with a carbonyl compound, and the reaction products of hydrogen cyanide which are formed therein are removed from the system and brought to atmospheric pressure. In this process, the handling of large amounts of hydrogen cyanide is avoided.

Abstract: A novel, one-pot procedure for the preparation of N-acryloyl-.alpha.-amino acids involves the steps of:(i) reacting a ketone, an ammonium salt, and a cyanide salt in water, optionally in the presence of ammonium hydroxide and a co-solvent, to form an aminonitrile;(ii) acryloylating the aminonitrile in aqueous media to afford an acrylamidonitrile; and(iii) hydrolyzing with aqueous acid the acrylamidonitrile to provide the N-acryloyl-.alpha.-amino acid.

Abstract: The invention relates to a process for the preparation of 2-cyanomethylcyclohexanone by1. converting cyclohexanone to a Mannich base with a secondary amine salt and formaldehyde2. converting the Mannich base to the corresponding cyanohydrin with a cyanide3. pyrolysing the cyanohydrin obtained in step 2, wherein the pyrolysis of the cyanohydrin is carried out in the presence of a polar, aprotic solvent having a boiling point of more than 140.degree. C. and/or sodium cyanide.

Abstract: Chiral aromatic cyanohydrins are prepared by treating an aromatic aldehyde with cyanide ions in the presence of an inert, aprotic solvent and a chiral cyclo(phenylalanyl-histidine) and an alcohol. The technique is especially useful for reducing the induction period when starting-up the process, increase the rate of reaction and to produce a product of increased enantiomeric selectivity.

Abstract: Enantiomeric selectivity is increased in chiral cyanohydrination of an aromatic aldehyde using a chiral cyclo(phenylalanylhistidine) catalyst by treating the (recycle) aldehyde to remove catalyst poisons or impurities which adversely effect enantiomeric selectivity.

Abstract: Novel 4-(.alpha.,.alpha.-dihydrocarbyl-.alpha.-cyano-methyl)-2,6-mono or dihydrocarbyl substituted phenols are prepared by reacting a 2,6-mono or dihydrocarbyl substituted phenol with a ketone and an alkali metal cyanide or an alkaline earth metal cyanide in an inert reaction solvent.

Abstract: Preparation of certain optically-active alpha-hydroxynitriles or a mixture enriched therein comprises treating an aldehyde with hydrogen cyanide in a substantially water-immiscible, aprotic solvent in the presence of a cyclo(D-phenylalanyl-D-histidine) as a catalyst.

Abstract: A cyanohydrination catalyst for the preparation of alphahydroxynitriles from aldehydes and ketones comprises a solid cyclo(D-phenylalanyl-D-histidine) dipeptide having a non-crystalline or amorphous component.

Abstract: A novel, one-pot procedure for the preparation of N-acryloyl-.alpha.-amino acids involves the steps of:(i) reacting a ketone, an ammonium salt, and a cyanide salt in water, optionally in the presence of ammonium hydroxide and a co-solvent, to form an aminonitrile;(ii) acryloylating the aminonitrile in aqueous media to afford an acrylamidonitrile; and(iii) hydrolyzing with aqueous acid the acrylamidonitrile to provide the N-acryloyl-.alpha.-amino acid.