摘要:
The present invention relates to a process for preparing 5-alkoxy-substituted oxazoles, in particular for preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.
摘要:
The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.
摘要:
The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.
摘要:
A process for preparing at least one unsaturated alcohol (B) comprises the steps (I) to (III) below: (I) reaction of at least one alkali metal hydroxide or alkaline earth metal hydroxide with at least one alcohol (A) in at least one organic solvent (L) to give a mixture (G-I) comprising at least the alcohol (A), the solvent (L) and an alkoxide (AL); (II) reaction of at least one carbonyl compound of the formula R—CO—R′ with at least one alkyne of the formula R″—C≡C—H and the mixture (G-I) obtained in step (I) to give a mixture (G-II) comprising at least the alcohol (A), the solvent (L) and an unsaturated alcohol (B); (III) distillation of the mixture (G-II) obtained in step (II) to give the alcohol or alcohols (B) and a mixture (G-III) comprising the solvent (L) and the alcohol (A), wherein the solvent (L) obtained in step (III) and the alcohol (A) obtained in step (III) are recycled as a mixture to step (I).
摘要:
In a process for reacting an organic compound in the presence of a catalyst comprising, as active metal, at least one metal of transition group VIII of the Periodic Table, either alone or together with at least one metal of transition group I or VII of the Periodic Table, in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst, applied to a support containing macropores, the support comprises, as a support component, boron(III) oxide in an amount of from 10 to 100% by weight, based on the total weight of the support.
摘要:
The process for preparing alkynediols of the formula (I) R1R2C(OH)—C≡C—C(OH)R1R2 (I) where R1, R2 are each independently H, or a C1-20-hydrocarbon radical which may be substituted by one or more C1-6-alkyls and/or be interrupted by nonadjacent heteroatoms and/or contain C—C double or triple bonds, by reacting compounds of the formula (II) R1—C(═O)—R2 (II) with acetylene in a polar aprotic solvent is carried out in the presence of basic alkali metal salts as catalysts.
摘要:
The invention relates to a method for producing alkyne diols by reacting ketones with acetylenic hydrocarbons in an organic solvent in the presence of a base which contains potassium alcoholates of primary and/or secondary alcohols. The alkyne diols are produced while forming adducts which precipitate out of the reaction mixture and which are comprised of alkyne monoalcohols and/or alkyne diols and a base. The stoichiometries of the reaction partners are selected such that gelatinous adducts are formed which comprise a spherical surface, whereby the reaction mixture remains agitable during the entire reaction.
摘要:
The present invention relates to a process for preparing acetylene alcohols of the general formula I where R1 and R2 may be the same or different and are each independently hydrogen, a saturated or a mono- or polyunsaturated C1-C30-alkyl, aryl, cycloalkylalkyl or cycloalkyl radical, each of which may optionally be substituted, or a group of the general formula (II) where R3 and R4 may be the same or different and are each independently hydrogen or a saturated or a mono- or polyunsaturated C1-C30-alkyl, aryl, cycloalky alkyl or cycloalkyl radical, each of which may optionally be substituted, and the dashed line may represent an additional double bond, by monoethynylating a ketone of the general formula R1—CO—R2 by (a) reacting lithium with a C1-C10-alkyl halide (b) feeding in acetylene gas (c) adding the ketone.
摘要:
Higher &agr;,&bgr;-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetates diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.
摘要:
Vinyl formate containing formic acid, acetaldehyde and water following synthesis is separated from formic acid and water in a first distillation stage and from acetaldehyde in a second stage to give pure vinyl formate.