110 THE CANNIZZARO REACTION however, that certain of the influences of structure upon the course of the reaction will operate in the crossed reaction as well. " EXPERIMENTAL CONDITIONS Concentration of Alkali For aromatic aldehydes, 50% alkali (sodium or potassium hydroxide) is most generally used, except for nitrobenzaldehydes, where 15-35% alkali is sufficient to bring about the reaction and, to control it so as to reduce the extent to which side products are formed. The use of less than about 50% alkali usually prolongs the time of the reaction atad, since the products are not sensitive to the action of caustic, offers no advantages. Alcoholic potassium hydroxide (about 25%) has been employed with success for the dismutation of methoxybenzaldehydes but appears to offer no particular advantages since o-methoxybenzalde-hyde is converted into the alcohol in excellent yield by the action of concentrated aqueous potassium hydroxide. Alcoholic alkali may be preferred, for difficultly soluble aldehydes. Solvents
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