Using 2-(5-bromo-2-pyridine)acetonitrile and 1,2-dibromoethane as raw materials and dimethyl sulfoxide as solvent,1-(5-bromo-2-pyridinyl)cyclopropane-1-carbonitrile(3)was obtained through alkylation,1-(5-bromo-2-pyridinyl)cyclopropanecarboxylic acid(2)was formed through hydrolysis,and 1-(5-bromo-2-pyridinyl)cyclopropanecarboxylic acid(methyl 1-(5-bromo-2-pyridinyl)cyclopropanecarboxylate(methyl 1-(5-bromopyridinyl)cyclopropanecarboxylate)was obtained through esterification.The reaction conditions for the chemistry were as follows:n(1,2-dibromoethane)∶n(2-(5-bromo-2-pyridine)acetonitrile)=1.02∶1.00,n(potassium hydroxide)∶n(3)=3.0∶1.0,solvent dimethylsulfoxide dosage of 1.8 L,peroxide dropping time of 2.0 h,crystallization temperature of-15 ℃,and pH 8.0.The yield of target compound 1 under optimised conditions was 69.5％and purity 98.6％(HPLC).The structure of the target compound was confirmed by melting point and 1H NMR characterisation.
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