Phenylmagnesium bromide reaction with ethyl benzoate

Triphenylethylene has been prepared by the reaction of phenylmagnesium bromide with benzyl benzoate, with desoxy-benzoin, or with ethyl pheaniylacetate, and by the reaction of diphenylketene-quinoline with benzaldehyde. The above procedure is an adaptation of that described by Hell and Wiegandt. ... 

Triphenylmethanol can also be prepared from the reaction of ethyl benzoate with phenylmagnesium bromide and by the reaction of diethylcarbonate... 

Esters react with 2 mol of Grignard reagent to give the salt of an alcohol. For example, reaction of ethyl benzoate with 2 mol of phenylmagnesium bromide gives a salt of triphenylmethanol. The first addition gives an intermediate, 3-7, which is unstable under the reaction conditions. 

One year later, in 1934, Vavon and co-workers [5] determined the relative reactivities of Grignard reagents with a different type of substrates benzoic acid esters. Steric requirements played a role when the alcohol component of the ester was changed from primary, to secondary, to tertiary the relative rates of reactions of ethylmagnesium bromide were 400 40 1, respectively. The relative rates of reaction of ethyl-, isopropyl-, n-butyl-, and phenylmagnesium bromide with ethyl benzoate decreased in this order. The reaction with rert-butylmagnesium chloride was reported to be extremely slow."... 

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