摘要:
A process for preparing bicyclic 1,3-diketones of the formula I where R1, R2, R3 and R4 are hydrogen, C1-C4-alkyl, C1-C4-alkoxy-carbonyl, halogen, cyano, nitro, C1-C4-alkylthio, C1-C4-alkylsulfenyl or C1-C4-alkylsulfonyl and Z is C1-C4-alkylene, O, S, N—R5 where R5 is C1-C4-alkyl or C1-C4-alkylcarbonyl, which comprises a) reacting a bicyclic olefin of the formula II with haloform in the presence of a base to give the ring-expanded product of the formula III where R1-R4 and Z are as defined above and X is halogen; b) hydrolyzing the allylic halogen of the compound of the formula III to the allyl alcohol of the formula IV c) oxidizing the allyl alcohol of the formula IV to the unsaturated ketone of the formula V d) reacting the ketone of the formula V with a nucleophilic ion Y− which stabilizes a negative charge to give the ketone of the formula VI e) hydrolyzing the ketone of the formula VI to the bicyclic 1,3-diketone of the formula I, novel intermediates and novel processes for preparing these intermediates are described.
摘要:
The invention relates to a method for producing β-ketoenol esters of the general formula (Ia) or (Ib), wherein Ar, Ra and Rb are defined as in claim 1. The inventive method is characterized by reacting an arylhalogenide of the general formula (II) with a 1,3-diketone of the general formula (III) or the tautomers thereof in a carbon monoxide atmosphere in the presence of an alkali and a catalyst that contains at least one transition metal of group VIII of the periodic system
摘要:
The present invention relates to a process for preparing a quaternary ammonium compound, which comprises reacting an amine compound containing at least one sp3-hybridized nitrogen atom with a dialkyl sulfate at ambient pressure with participation of both alkyl groups of the dialkyl sulfate and, if appropriate, subjecting the resulting quaternary ammonium compound containing sulfate anions to an anion exchange.
摘要:
In a continuous process for the preparation of alkyl nitrites and dinitrites, an alkanol or dialkanol is first mixed with an aqueous mineral acid, the reaction mixture obtained is then reacted with an inorganic nitrite and the product obtained can then be isolated immediately.