Preparation method for alkyl/benzyl/aryl urea compounds through heterogeneous-phase catalysis

Abstract

The invention discloses a preparation method for formula (I) compounds, and the compounds are obtained by reacting a formula (II) compound with a formula (III) compound in a solvent in carbon monoxide atmosphere under catalysis of a heterogeneous-phase palladium catalyst. The reaction related in the method does not need strict waterless oxygen-free condition and does not need high pressure, is convenient and simple to operate, and possesses extremely good tolerance and universality on functional groups. Also the catalyst is extremely small in usage amount and is recoverable, reaction cost is low, and the preparation method is widely applicable to prepare alkyl/benzyl/aryl urea compounds. The formula (I) is R<1>-NH-CO-NR<3>-R<2>, the formula (II) is R<1>-N3, and the formula (III) is HNR<3>-R<2>, wherein R<1> and R<2> are same or different, and are mutually independently selected from aryl, heteroaryl, cycloalkyl, heterocyclic groups, alkyl, alkenyl, alkynyl, arylalkyl, heteroaryl alkyl, cycloalkyl alkyl, heterocyclic-group alkyl, aryl alkenyl, heteroaryl alkenyl, cycloalkyl alkenyl and heterocyclic-group alkenyl; and R<3> is selected from H or R<2>, or R<3> and R<2> are in connection for forming a ring.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a method for preparing heterogeneously catalyzed alkyl / benzyl / aryl urea compounds. Background technique [0002] Alkyl / benzyl / aryl urea compounds are a very important class of organic compounds, which are widely used in the fields of medicine, pesticides and polymer functional materials. For example, in the field of pesticides, nearly 50 types of alkyl / benzyl / aryl urea compounds have been commercialized as herbicides, accounting for a large sales share of herbicides. Diuron alone ranks 18th in terms of sales This kind of compound can achieve herbicidal effect by inhibiting plant photosynthesis or cell division. [0003] For a long time, people have been looking for simple, efficient and low-cost methods for the synthesis of alkyl / benzyl / aryl urea compounds. Currently known synthetic methods are still very limited, mainly prepared by the following methods: [0004] 1. Starting ...

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Problems solved by technology

[0005] The above-mentioned methods all have major deficiencies: 1) need to use highly toxic solvents, such as method 1; 2) the general applicability of the method product of transition metal catalysis is not good, the limitation is poor, or at least one end is an aryl group, Or the product is a symmetrical alkyl urea, and the reaction cannot react to secondary amines, such as methods two, three, and four; 3) generally all used are expensive rhodium catalysts, and all are homogeneous catalysts, and cannot Recycling, high cost, such as method four

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