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UXIVERSITY]
VI. PRODUCTION OF ALDEHYDES -4KD KETONES FROM NITRO PARAFFINS ICEKSETH JOHSSON
WITH
ED. F. DEGERING
Received July 11, 19@
Primary and secondary nitro paraffins are acidic in nature and form sodium salts. When mineral acid is added to these sodium salts, the nitro paraffins are regenerated. The action is different, however, when the sodium salts are added to an excess of the acid. In the latter case aldehydes or ketones are formed with the evolution of nitrous oxide. The action may be summarized by the following equation but the mechanism of the reaction is not known:
+ 2H2S04+ 2RCHO + NzO + 2NaHS04 + H20, or 0)ONa + 2H&O4 + 2Rz:CO + NzO + 2NaHS04 + HzQ
2RCH:N(+ 0)ONa 2RzC:K(+
Xef (2) prepared acetaldehyde from nitroethane by adding a 10% solution of the sodium salt to 20% sulfuric acid. The yield was 70%. Kef also prepared acetone by this method. Konowaloff (I) prepared ketones from the sodium salts of several nitro paraffins but his reactions were probably accompanied by simultaneous reduction, as in several cases he dropped the salt into a mixture of zinc and acetic acid, and in another, into an acid solution of stannous chloride. EXPERIMEXTAL
The general procedure is: one-sixth of a mole of nitro paraffin is dissolved in 150 ml. of a solution containing 8 g. of sodium hydroxide, and then added dropwise to an ice cold mixture of 25 ml. of concentrated sulfuric acid in 160 ml. of water. Efficient agitstion is used during the addition. Gas is evolved as the solution is added. The mixture is rectified, and the aldehyde or ketone determined quantitatively by its reaction with hydrosylamine hydrochloride. The procedure n-as modified in one series of evperiinents by using 7 g. of calciuni, hydroxide instead of the sodium hydroxide. By these two procedures the aldehydes and ketones available from nitroethane, %nitropropane, 1-nitropropane, 1-nitrobutane, 2-nitrobutane, and 1-nitro-2-methylpropane were prepared. With the exception of isobutyraldehyde, all of these aldehydes and ketones were obtained in 80-85% yield. It might be noted t h a t in several attempts t o regenerate the nitro paraffin, from the sodium salt, the recovery of nitro paraffin was limited to about 85%. The cslcium salts gave as good yields as the sodium salts, but more time had t o be given for the reaction between the calcium hydroxide and nitro paraffins in order t o assure an appreciable concentration of the enolic or salt form. The calcium salts of the nitrobutanes are not very soluble in water. The decomposition of the salts of the nitro alkanes is practically instantaneous. The nitrous oxide is evolved as soon as the salt solution comes in contsct with the acid. The data on experimental procedure and yields are summarized in Table I. 10
11
NITRO PARAFFISS
TABLE I PREPARATION OF
ALDEHYDES AND
NO.
NITRO PARAFFIN
1. 2. 3. 4.
Nitroethane 1-Nitropropane 1-Nitropropane 2-Nitropropane 2-Nitropropane 2-Kitropropane 1-Nitrobutane 1-Nitrobutane 1-Kitrobatane 2-Sitrobutane 2-Sitrobutane 1-Nitro-2-methylpropane 1-Nitro-2-niethylpropa1ie
5. 6. 7. 8. 9. 10. 11. 12. 13.
ICETONES FROM CERTAIX N I T R O PARAFFINS
--
SALT USED
Calcium Calcium Sodium Calcium Sodium Sodium Calcium Sodium Sodium Calcium Sodium Calcium Sodium
PRODUCT
70YIELD
Ethanal Propannl Propanal Propanone Propanone Propanone Butanal Butanal Butanal Butanone Butnnone 2-blethylpropanal 2-Metliylpropanal
77 79.5 80 83.5 83.7 73 S5 85 45.5 85.5 s2 36 32.4
_-
The salt was prepared, added t o the sulfuric acid, and the mixture distilled into a solution of hydroxylamine hydrochloride. With KO.9 no excess acid was used. A representntive mix for the salt solution is 103 g. of 1-nitrobutane,45 g . of KnOH, and 500 ml. of water, which is added t o 100 g. of HzSO4 in 500 ml. of water. -411 produets were identified a s t h e oxime. SUKMARY
Aldehydes and ketones were prepared from primary and secondary nitro paraffins by the action of their sodium or calcium salts on sulfuric acid. The conversions were 8 0 4 5 % . The procedure listed was used in the preparation of acetone, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and ethyl methyl ketone. The reaction is generally applicable for the syntheses of aldehydes and ketones. LAFAYETTE, IND.
REFEREXCES (1) KNOWALOFF, J . Chem. Soc., 66, 265 (1894, abstracts). (2) NEF, Ann., 280, 263 (1894).
