Abstract: An improvement on the preparation of vinylmagnesium chloride is described. The new approach prevents vinyl chloride from escaping and simplifies the operation. The important advantage is that it would get rid of -45°C deep cooling. The Grignard reagent was used to test its application and qualification for the synthesis of vimyl-β-ionol or 6-methoxy-1-vinyl-1-tetralol. The former is an intermediate of isotretinoin and the latter is an intermediate of mifepristone norgestrel or norgetriene.

Key words: Vinylmagnesium chloride, Vinylmagnesium chloride, Deep cooling, Deep cooling, Isotretinoin, Isotretinoin, Mifepristone, Mifepristone