摘要:
The present invention relates to a process for preparing ethylenediamine (EDA), where the process comprises the steps a) to c). In step a), formaldehyde is reacted with hydrocyanic acid (HCN) to form formaldehyde cyanohydrin (FACH), where the hydrocyanic acid is completely free or largely free of sulfur dioxide (SO2). The FACH prepared in this way is reacted with ammonia (NH3) to form aminoacetonitrile (AAN) in step b), whereupon a hydrogenation of AAN in the presence of a catalyst to form EDA is carried out in step c).
摘要:
A process is described for preparing adiponitrile by hydrocyanating 1,3-butadiene over a catalyst, by, in a first process step, hydrocyanating 1,3-butadiene to 3-pentenenitrile over at least one nickel(0) catalyst, and, in a second process step, hydrocyanating 3-pentenenitrile to adiponitrile over at least one nickel(0) catalyst with addition of at least one Lewis acid, wherein at least one of the at least one nickel(0) catalysts used in the particular process steps is transferred into the other process step.
摘要:
The present invention relates to a process for preparing 3-cyano-3,5,5-trimethylcyclohexanone (isophoronenitrile) by reacting isophorone with hydrogen cyanide in the presence of a base as a catalyst to obtain a crude isophoronenitrile product, and subsequently distilling the crude isophoronenitrile product, with the addition before distillation of at least one specific sulfonic acid or specific carboxylic acid. In addition, the present invention relates to the use of a specific sulfonic acid or of a specific carboxylic acid as a neutralizing agent before distillation of a crude isophoronenitrile product which has been obtained by reacting isophorone with hydrogen cyanide in the presence of a base as a catalyst, in order to avoid precipitates in the neutralization of the base used as a catalyst with an acid.
摘要:
A process for cyanating an aldehyde is provided. The process comprises reacting the aldehyde with: i) a cyanide source which does not comprise a Si—CN bond or a C—(C═O)—CN moiety; and ii) a substrate susceptible to nucleophilic attack not comprising a halogen leaving group; in the presence of a chiral catalyst. Preferably, the chiral catalyst is a chiral vanadium or titanium catalyst. The cyanide source is preferably an alkali metal cyanide and the substrate susceptible to nucleophilic attack not comprising a halogen leaving group is a carboxylic anhydride.
摘要:
The invention relates to a continuous process, carried out in two steps, for the cyanoalkylation of compounds having one or more NH functions by reaction thereof with carbonyl compounds and hydrocyanic acid, in which the first step is carried out without pressure at a temperature which is below the boiling point of the reaction mixture.
摘要:
3-Amino-2-hydroxy-4-phenylbutyronitrile derivatives represented by the formula (3) may be prepared by reacting an aminoaldehyde derivative represented by the formula (1) with a cyanohydrin derivative represented by the formula (2) in the presence of a metallic compound, base, or acid; ##STR1## wherein R.sup.1 and R.sup.2 each independently represents a hydrogen atom or a protective group for an amino group, R.sup.3 and R.sup.4 each represents an alkyl or cycloalkyl group or R.sup.3 and R.sup.4 together form a tetramethylene or pentamethylene group.
摘要:
A process for the condensation of an aldehyde with hydrogen cyanide in the presence of a buffer is disclosed. The buffer advantageously allows the condensation reaction to occur at a pH equal to or above 4.0 and in the absence of amines.
摘要:
Optically active cyanohydrins are prepared by addition of hydrogen cyanide to aldehydes in the presence of catalysts which comprise the dipeptide derivative represented by the formula ##STR1## wherein R.sup.1 represents an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a methyl group, a benzyl group or a phenyl group, R.sup.2 represents a benzyl group, an indol-3-ylmethyl group, an isopropyl group, an isobutyl group or a phenyl group, R.sup.3 represents a lower alkoxy group, a hydroxy group or a mono- or di-lower alkylamino group, R.sup.4 represents a hydrogen atom, or R.sup.2 and R.sup.4 are bonded together at their terminals to form a CH.sub.2 CH.sub.2 CH.sub.2 group, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are the same or different, and each represents a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group or R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, or R.sup.7 and R.sup.8 are bonded together at their terminals to form CH.dbd.CH--CH.dbd.CH or OCH.sub.2 O, and * denotes an absolute configuration of S or R, and a titanium (IV) alkoxide.
摘要:
A process for producing a mandelonitrile compound represented by the following formula (2), comprising a step of reacting a benzaldehyde compound represented by the following formula (1) with at least one member selected from the group consisting of metal cyanides and hydrogen cyanide in the presence of a phase transfer catalyst in a solvent.
摘要:
The present invention relates to a process for the preparation of dinitriles by hydrocyanation of unsaturated nitrile compounds in the presence of a catalyst based on a metal element in the zero oxidation state and on organophosphorus ligands;the invention relates more particularly to a process for the recovery from the hydrocyanation medium of a catalyst for the hydrocyanation of unsaturated nitrites to dinitriles. It consists in controlling the concentration of unsaturated nitrites in the reaction medium resulting from the hydrocyanation reaction in order to obtain a concentration by weight of unsaturated nitrites of less than 20% in the said medium, and in then feeding the said medium to a stage of settling into two upper and lower phases. The lower phase comprises most of the catalytic system, while the upper phase is composed essentially of the dinitriles.