Catalysts and methods for making cyclic carbonates are disclosed. The catalyst may include at least one polymer quaternary ammonium salt, at least one metal halide and silica gel. The method of making the cyclic carbonates may include forming a mixture that includes the catalyst and an epoxide, and contacting the mixture with carbon dioxide in a reactor under conditions to form the propylene carbonate.

Processes for preparation of a high purity cyproconazole, i.e., (2RS,3RS;2RS,3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl) butan-2-ol; and its compound i.e., 2-(4-chlorophenyl)-2-(1-cyclopropylethyl) oxirane generally includes reacting a ketone of formula (II) with a sulfonium salt in the presence of a base to obtain the oxirane compound of formula (III); ##STR00001## wherein the sulfonium salt is obtained by reacting dimethyl sulfide and dimethyl sulfate in the presence of water; followed by reacting the oxirane compound of formula (III) with 1,2,4-triazole or its alkali metal salt to obtain a crude cyproconazole; and treating the crude cyproconazole with an aqueous alcohol to obtain a higher purity cyproconazole.

Processes for preparation of a high purity cyproconazole, i.e., (2RS,3RS;2RS,3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl) butan-2-ol; and its compound i.e., 2-(4-chlorophenyl)-2-(1-cyclopropylethyl) oxirane generally includes reacting a ketone of formula (II) with a sulfonium salt in the presence of a base to obtain the oxirane compound of formula (III); ##STR00001## wherein the sulfonium salt is obtained by reacting dimethyl sulfide and dimethyl sulfate in the presence of water; followed by reacting the oxirane compound of formula (III) with 1,2,4-triazole or its alkali metal salt to obtain a crude cyproconazole; and treating the crude cyproconazole with an aqueous alcohol to obtain a higher purity cyproconazole.