Organic Lab Reactions 118

Organic Lab Reactions 118 - 65-75° The mixture is then...

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EXPERIMENTAL PROCEDURES 113 yield of pure acid, m.p. 146° after recrystallization from water, is 15.2 g. (96%). A similar procedure is followed with the m- and p-nitrobenzaldehydes, comparable yields being obtained. The Crossed Cannizzaro Reaction. 90 - * Into a 2-1. three-necked flask fitted with a dropping funnel, mercury-sealed stirrer, and reflux con- denser are introduced one mole of the aromatic aldehyde, 700 cc. of methanol, and 100 cc. (1.3 moles) of formalin. The solution is heated to 65°, and the flask is surrounded by cold water while a solution of 120 g. of sodium hydroxide or 168 g. (3 moles) of potassium hydroxide in 120 cc. of water is added rapidly, the temperature being maintained at
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Unformatted text preview: 65-75°. The mixture is then heated at 75° for forty minutes and finally refluxed for twenty minutes. The solution is cooled, diluted with 300 cc. of water, the oily layer separated, and the aqueous layer extracted with four 150-co. portions of benzene. The combined oil and benzene extracts are dried, the benzene removed, and the product distilled under reduced pressure. The yields are 85-95%. Acidification.of the alkaline solution yields 2-5% of the aromatic acid. * The preparation of p-tolyl carbinol by the crossed Cannizzaro reaction is described in Organic Syntheses, CoU. Vol. 2, 590 (1943)....
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