Patent ID: 9475794
Filing Date: 2016-10-25
CPC Classification: C07D

Claim Text:
1. A process for the preparation of a Form I crystalline polymorph of imidacloprid exhibiting an X-ray powder diffraction pattern having characteristic peaks (expressed in degrees 2θ (+/−0.2°θ) at one or more of the following positions: 9.560, 16.040, 19.220, 19.720, 23.560, 24.440, 25.740, 29.020 and 29.100, or exhibiting a Differential Scanning Calorimetry (DSC) thermogram which is characterized by a predominant endotherm peak at about 145.7° C., or both, comprising: (i) dissolving imidacloprid in an amount of aqueous solvent or mixture of solvents appropriate to obtain an aqueous solution, wherein the aqueous solvent is selected from the group consisting of methanol, ethanol, tetrahydrofuran, acetonitrile, methylene chloride, isopropyl alcohol, acetone, N,N-dimethyl-Formamide, and dimethyl sulfoxide; (ii) cooling the aqueous solution slowly, thereby forming crystals of polymorph Form I of imidacloprid; (iii) isolating the crystals.