Synthetic method of p-hydroxybenzonitrile

The invention discloses a synthesis method of p-hydroxybenzonitrile, which comprises the following steps: carrying out diazotization reaction on p-hydroxyaniline to form a diazo compound, and reactingthe diazo compound with cuprous chloride and sodium cyanide to obtain the p-hydroxybenzonitrile. The p-hydroxyaniline is obtained by hydrogen reduction of p-nitrosophenol, and the p-nitrosophenol isobtained by nitrosation of phenol. The reaction temperature of each step is low, the reaction conditions are mild, and the reaction power consumption is greatly reduced. The reaction can be carried out by adopting a conventional reaction kettle, the equipment requirement is low, and the investment is small. According to the method, a dehydrating agent and filler are not used, only a small amount of catalyst is used, meanwhile, the catalyst can be recycled, the solid waste amount is small, only a small amount of solid catalyst is generated, and no difficult-to-treat wastewater is generated. 本发明公开了一种对羟基苯甲腈的合成方法，包括对羟基苯胺重氮