Preparation methods of aromatic hydroxylamine compound and N-aromatic acylated hydroxylamine compound

Abstract

The invention discloses a preparation method of aromatic hydroxylamine compound as shown in general formula (I). The preparation method comprises the following steps: performing reduction reaction on a compound as shown in formula (II) and hydrazine hydrate in an organic solvent in the presence of a reduction catalyst, wherein the organic solvent is at least one of aliphatic ether and cyclic ether; R1 is hydrogen, halogen, cyano, C1-C4 alkyl, C1-C4 haloalkyl or -CH2-O-R2, wherein R2 is substituted or unsubstituted phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrazolyl or imidazolyl; in addition, the invention further discloses a preparation method of N-aromatic acylated hydroxylamine compound as shown in formula (III). According to the preparation methods of aromatic hydroxylamine compound and N-aromatic acylated hydroxylamine compound, the reduction reaction has a conversion rate of above 99% and a selectivity of above 99%; the N-acylation reaction has a conversion rate of above 99% and a selectivity of above 98%.

Description

technical field [0001] The present invention relates to a preparation method of an aromatic hydroxylamine compound and a preparation method of an N-acylated aromatic hydroxylamine compound. Background technique [0002] At present, there are many preparation methods of N-[2-[[1-(4-chlorophenyl)pyrazol-3-yl]oxymethyl]phenyl]hydroxylamine reported both at home and abroad, and the method adopted in its preparation method Most of the reducing agents are metal zinc, but the production of aromatic hydroxylamine compounds with this reducing agent will produce a large amount of three wastes, and the selectivity of the reduction products is not high, which is not conducive to industrial production. [0003] WO 96 / 22967 discloses a method for the preparation of aromatic hydroxylamine compounds. The method uses carbon-supported noble metal platinum or palladium as a catalyst to carry out catalytic hydrogenation of nitrobenzene compounds under the conditions of heterocyclic amines such ...

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Problems solved by technology

[0002] At present, there are many preparation methods of N-[2-[[1-(4-chlorophenyl)pyrazol-3-yl]oxymethyl]phenyl]hydroxylamine reported both at home and abroad, and the method adopted in its preparation method Most of the reducing agents are metal zinc, but the production of aromatic hydroxylamine compounds using this reducing agent will produce a large amount of three wastes, and the selectivity of the reduction products is not high, which is not conducive to industrial production

[0003] WO 96 / 22967 discloses a method for the preparation of aromatic hydroxylamine compounds. The method uses carbon-supported noble metal platinum or palladium as a catalyst to carry out catalytic hydrogenation of nitrobenzene compounds under the conditions of heterocyclic amines such as N-methylmorpholine Reaction, obtained the aromatic hydroxylamine compound of higher yield; But need to use a large amount of N-methylmorpholines to dissolve raw material in this method, the separation of the product after reaction needs complex after-treatment operation at the same time, as needing at higher Distillation at low temperature removes N-methylmorpholine, while aromatic hydroxylamine compounds are mostly unstable at high temperature, and the recycling of noble metal catalysts will lose their activity due to poisoning

WO 99 / 12911 also discloses the use of carbon-supported noble metal platinum or palladium as a catalyst. The difference is that adding aliphatic amines (based on aromatic nitro compounds, the amount of aliphatic amines is 1-15 moles) in the reaction system can obtain relatively High yield, the catalyst described in this method can be recycled without loss of activity, but there is also the need to distill and recover fatty amines at higher temperatures

[0004] WO 2012 / 038392 and WO 2012 / 120029 disclose the use of supported ruthenium and rhodium as catalysts, and hydrazine hydrate as a reducing agent to reduce nitrobenzene compounds. This method can obtain phenylhydroxylamine compounds with high selectivity, but the price of these two types of catalysts very expensive, high cost

[0005] Generally, aromatic nitro compounds selectively synthesize aromatic hydroxylamine compounds and can be reduced by borohydride (CN1772728; Chem Lett.7,1069 (1986); Synthetic Communications.27,3497 (1997); Synthetic Communications.27,1547 (1997)), tin complex reduction (Tetrahedron.46,587(1990)), phosphite reduction (Tetrahedron.34,213(1978)) and other methods are carried out, but the above methods all have low product yield, poor selectivity and narrow application range and other defects

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