Reaction CXXVI.—-Action of Hydroxylamine on Aldehydes and Ketones

Reaction CXXVI. Action of Hydroxylamine on Aldehydes and Ketones. 

RRjCO + NH2OH -RRiC = NOH + H20. Hydroxylamine hydrochloride (NH20H.HC1) is generally used in most cases the free base is liberated by the subsequent addition of the theoretical quantity of a basic substance (caustic potash, sodium carbonate, etc.). With aldehydes it is advisable to reduce the quantity of 

10 gms. (excess) of hydroxylamine hydrochloride, dissolved in the minimum amount of water, are added to 10 gms. (1 mol.) of camphor 

14 gms. of caustic soda dissolved in 40 c.cs. of water and 21 gms. of benzaldehyde are mixed in a flask. 14 gms. of hydroxylamine hydrochloride are added in small portions at a time, the mixture being continually shaken. The benzaldehyde gradually disappears, and some heat is developed. On cooling, a crystalline mass separates out. Sufficient water is added to redissolve, and carbon dioxide is passed in until saturated. The oxime then separates, and is extracted with ether the ethereal solution is dried over anhydrous sodium sulphate. The ether is removed (see p. 36), and the residue distilled under greatly diminished pressure. 

Reaction CXXVII. Action of Acids, Acid Chlorides, Anhydrides, and Phosphorus Pentachloride on Oximes. (B., 23,11 J. C. S., 117,1045.)— Aldoximes (oximes obtained from aldehydes) exist in two stereoisomeric forms depending on the relative position of the OH group. 

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