2-Butanone oxime → 2-(Trimethylsilylmethyloxyimino)butane

To the above obtained dispersion of metallic sodium was added 34.8 g (0.4 mole) of methylethylketoxime and the reaction mixture was heated at 60° to 80° C. for about 180 minutes followed by removal of toluene under reduced pressure to give pasty sodium salt of methylethylketoxime. Then, this sodium salt of methylethylketoxime was dispersed in a mixture of 49.2 g (0.4 mole) of trimethylchloromethylsilane and 100 ml of N,N-dimethylformamide and heated at 70° to 80° C. for 3 hours with agitation. The reaction mixture after completion of the reaction was washed with water to remove sodium chloride formed as the by-product and N,N-dimethylformamide and the residue was extracted with diethyl ether followed by evaporation of the ether to give a crude product which was further distilled under reduced pressure to give 48.4 g of a liquid product boiling at 84° C. under 50 mmHg. This product is referred to as compound S-I hereinafter.