When treated with cyanogen, benzylmagnesium chloride has been found to yield o- tolunitrile. This new o-substitution reaction has been found to occur also with cyanogen and three other benzyl-type Grignard reagents. Particularly interesting is the case with 2, 6- dimethylbenzylmagnesiuni chloride, whose substitution by cyanogen yields the non- aromatic triene VII.
