FIELD: production of herbicides. SUBSTANCE: invention describes improved method of preparing cyclopropyl nitrile which is intermediate product in the preparation of herbicides. The method comprises mixing 4- halobutyronitrile with at least 0.25 moles of inorganic salt which is alkali metal halide, sulfate or carbonate selected from Na, K or Li, and with catalytic amount of water in the presence of aprotic polar solvent at temperature between 50 and 100 C, and the whole is then treated with alkali metal base at elevated temperature. Reaction mixture is further treated by decreasing temperature to room temperature followed by neutralization of reaction mixture, dilution of neutralized mixture with water and recovery of cyclopropyl nitrile by azeotropic distillation. The method is suitable for large-scale production and simplifies recovery of the desired product. EFFECT: simplified method. 10 cl, 8 ex, 1 tbl
