PROCESS FOR PRODUCTION OF PHENYLTRIAZOLINONE

摘要

Disclosed is a novel phenyltriazolinone production process which enables to produce a highly pure phenyltriazolinone in high yield in an simpler and safer manner and at a lower cost by using a more inexpensive raw material. Specifically disclosed is a process for producing a phenyltriazolinone, which comprises the steps of: reacting an aniline with a nitrite salt to produce a diazonium salt; reducing the diazonium salt with a sulfite salt or a bisulfite salt; hydrolyzing the reduced product to produce a phenylhydrazine; reacting the phenylhydrazine with formaldehyde in the presence of a catalyst at pH 5-10 to produce a formaldehyde-phenylhydrazone; reacting the formaldehyde-phenylhydrazone (3) with cyanic acid to produce a phenyltriazolidinone; and reacting the phenyltriazolidinone (4) with an oxidizing agent selected from a hypohalous acid salt and oxygen in the absence of any catalyst or in the presence of an oxidation catalyst.