It is shown in the present paper that benzylmagnesium chloride reacts with 3- phenylquinazoldne-4 (I) forming IV. This reaction is remarkable if it is compared with the ones that occur when acetanthranil,(V) l or. 1, 2-&methylquinazolone-4 (VI) 2 are treated with Grignard reagents for, in each of the latter cases, addition to a carbonyl group takes place. It is felt, however, that the apparently anomalous behavior of I can be explained in ...