A Method for the Preparation of Grignard Compounds in Hydrocarbon Solution

Abstract

1,084,345. Preparing and utilizing Grignard reagents. M & T CHEMICALS Inc. July 28, 1966 [July 29, 1965], No. 33988/66. Headings C2C and C2J. [Also in Division C3] Grignard reagents RMgX where R=alkyl or aryl and X=Cl, Br or I are prepared by reacting an alkyl or aryl chloride, bromide or iodide with magnesium (Grignard grade or triply sublimed granules) in the presence of a tertiary amine and a hydrocarbon solvent, the Grignard reagent being formed in solution in the hydrocarbon. The reaction temperature is maintained at about 50‹ C. and the reaction system may be closed to prevent evaporation of amine. Benzene, toluene and hexane are named as solvents and trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine and dimethylaniline as suitable amines. The ratio of Grignard compound to tertiary amine can be between 1A0 : 0A1 and 1A0 : 2A0. In the examples, ethyl magnesium bromide is prepared in triethylamine-benzene solution (1); n-butyl magnesium chloride in triethylaminetoluene solution (II); and ethyl magnesium bromide in dimethylaniline-hexane solution (III). The ethyl magnesium bromide prepared in Example 1, is reacted in its solution with benzaldehyde and acetophenone to give ethylphenylcarbinol and ethylmethylphenylcarbinol respectively, and the ethylmagnesium bromide of Example 3 is reacted with tin tetrachloride to give tetraethyl tin.