PURPOSE: To effectively produce the subject compounds by forming a complex from a nitrile and a boron trihalide, then reacting the complex with aniline in the presence of a Lewis acid, spraying an inert gas to the resulting reaction mixture and cooling the sprayed reaction mixture.

CONSTITUTION: A nitrile of formula II (wherein R is a 3-6C cycloalkyl or a 1-6C haloalkyl) is reacted with a boron trihalide in a solvent to form a 1:1 dative complex. Then, this complex is reacted with aniline in the presence of a Lewis acid (particularly preferred being aluminum chloride) to form a reaction mixture. An inert gas such as nitrogen is sprayed on to this reaction mixture at high temperatures for about 1-24 hours (preferably 12 hours). Subsequently, the sprayed reaction mixture is cooled with water to obtain an o- aminopherayl ketone of formula I. By using this method, from a 4- halobutyronitrile is obtained a compound of formula III (X is Cl of Br), which is further reacted with at least one molar equivalent aqueous base in the presence of a phase transfer catalyst and, optionally, an organic solvent to obtain o-aminophenyl cyclopropyl ketone.