摘要:
The invention relates to a process for the preparation of high yields of 5-oxohexane nitriles with minimum formation of 1 undesired isomer. Such nitriles may be utilized as starting materials for the preparation of pharmaceutical and agrochemical intermediates and as well as final products. The process comprises reacting a methyl ketone and an .alpha.,.beta.-unsaturated nitrile in the presence of a catalytically effective amount of a strong base. One of the products which may be created by the process is 2,4-dimethyl-5-oxohexane nitrile.
摘要:
The invention relates to a process for the preparation of high yields of 5-oxohexane nitriles with minimum formation of 1 undesired isomer. Such nitriles may be utilized as starting materials for the preparation of pharmaceutical and agrochemical intermediates and as well as final products. The process comprises reacting a methyl ketone and an .alpha.,.beta.-unsaturated nitrile in the presence of a catalytically effective amount of a strong base. One of the products which may be created by the process is 2,4-dimethyl-5-oxohexane nitrile.
摘要:
Process for the preparation of substituted pyridines by allowing 1-aza-1,3-butadienes to react, in the presence of a catalytic amount of secondary amine and acid, with an aldehyde or ketone, and new 1-aza-1,3-butadienes which are used in this process. Said pyridines can be obtained in high yield in a simple process with a short reaction time. The 1-aza-1,3-butadiene can, if so desired, be prepared in situ from an imine and an aldehyde.
摘要:
The invention relates to a method for preparing an .alpha.-alkylcinnamaldehyde via aldol concensation of a benzaldehyde and an alkanal, with pyrrolidine being employed as a catalyst. The method is suitable, in particular, for preparing .alpha.-hexylcinnamaldehyde by aldol condensation of benzaldehyde and n-octanal, in particular for preparing .alpha.-hexylcinnamaldehyde of olfactory quality, since it was found that, in the method according to the invention, relatively little .alpha.-hexyldecenal, the aldol condensation product of n-octanal, is formed. Preferably, the aldol condensation is carried out without a solvent in the presence of an acid, and the alkanal is metered in over time to a mixture which contains pyrrolidine and benzaldehyde.
摘要:
Process for the preparation of N-alkyl-N,O-diacetyl hydroxylamine, for instance N-methyl-N,O-diacetyl hydroxylamine, by catalytic reduction of a nitroalkane, for instance nitromethane, in the presence of acetic anhydride. As catalyst preferably a platinum on alumina catalyst is used. The invention provides a simple one-step process for the preparation of N-alkyl-N,O-diacetyl hydroxylamine in a relatively concentrated reaction medium.
摘要:
Process for the preparation of 3-phenylpropanal in which cinnamaldehyde is hydrogenated with the aid of a Pd-containing catalyst in the presence of a small amount of water. A high yield and a high selectivity are obtained in a commercially attractive process. The reaction mixture obtained can without intermediate further processing be subjected to an oxidation in which the cinnamaldehyde is oxidized to 3-phenylpropionic acid with a high degree of conversion and a high selectivity. The combination of the two process steps constitutes a simple, commercially attractive process for the preparation of 3-phenylpropionic acid using cinnamaldehyde as a starting material. The resulting 3-phenyl-propionic acid product may serve as an intermediate reagent in the synthesis of anti-viral pharmaceuticals, particularly HIV protease inhibitors.
摘要:
The invention relates to a dendritic macromolecule comprising a core and branches emanating from the core wherein the branches are based on vinyl cyanide and/or fumaryl dinatrile units. The invention also relates to processes for preparing these dendritic macromolecules. The dendritic macromolecules according to the invention are not sensitive to degradation through hydrolysis reactions and are also very stable at a high temperature. The processes are very suitable for large scale production of the dendritic macromolecules without requiring purification of reaction intermediates.
摘要:
Method for the preparation of N-alkoxy-(tetra- or hexahydro)-phthalimide according to formula I ##STR1## R.sub.1 being methyl or ethyl and R.sub.2 and R.sub.3 being each independently of one another hydrogen or alkyl with 1-4 C atoms or R.sub.2 and R.sub.3 together with the carbon atom to which they are bonded forming a ring with 5 or 6 C atoms, wherein the salt of the corresponding N-hydroxy-(tetrahydro- or hexahydro)-phthalimide according to formula II: ##STR2## with R.sub.2 and R.sub.3 as defined above and M being an alkali metal, is brought into contact with R.sub.1 Cl as alkylating agent, wherein R.sub.1 has the aforementioned meaning. The N-alkoxy-(tetra- or hexahydro)-phthalimide can afterwards be converted with the aid of hydroxylamine sulphate into the corresponding alkoxyamine after which the alkoxyamine obtained can be isolated. In this manner a simple and commercially attractive process for the preparation of O-(m)ethylhydroxylamine can be implemented.
摘要:
Process for the .alpha.-chlorination of phenylacetonitriles, for example benzyl cyanide, in which the phenylacetonitrile is contacted with a suitable chlorinating agent, sulphuryl chloride or chlorine gas, while an amount of strong acid, preferably HCl, is also present in the reaction mixture. The induction time and the reaction rate are dependent on, among other factors, the concentration of the acid. Preferably, the reaction is carried out under pressure. The reaction is well controllable.
摘要:
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.