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[ C O V rRIRUTION FROM THE
CHEMISTRY 1)EPARTMENT
O F THE UNIVERSITY O F
Vol. 74
KANSAS]
The Schmidt Reaction Applied to Aldehydes and Epoxides' I-(\' \\
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.4ND C A L V I N
11.Y A N D E R W E R F
Reaction of benzaldehyde with hydrazoic acid i n the presence of a low concentration of sulfuric acid affords mainly benzonitrile together with a small yield of formarillide. With an increased amount of sulfuric acid, formanilide becomes the major product and benzonitrile the minor product. This behavior also holds true for p-tolualdehyde and p-chlot obenzaldehyde. Anisaldehyde and p-iiitrobenzaldehyde, on the other hand, give the nitrile as the main product even at the higher sulfuric acid concentration. An interpretation of these results is offered. The acid-catalyzed reaction of styrene oxide a i t h hydrazoic acid to give aniline, and the SNZtype of reaction of styrene oxide with the azide ion to give a product, CsH9N30, which affords P-phenyl-6-arninoethanol on hydrogenolysis are also described.
4 s early as 1926 Schmidt3 observed that the action of hydrazoic acid on benzaldehyde in the presence of sulfuric acid produced both benzonitrile and formanilide; he reported further that the yields of benzonitrile and formanilide shif tecl from 70% and 13yoto 5% and SO%, respectively, when the molar ratio of sulfuric acid to benzaldehyde was changed from 0.72 to 5.4. Apparently this curious shift in the relative percentages of reaction products with change in sulfuric acid concentration has escaped further investigation and is as yet completely unexplained. In an attempt to investigate the generality of this type of shift in the predominant products of the reaction arid to obtain evidence for a mechanism which would explain it, we have repeated Schmidt's work on benzaldehyde and have studied four additional aldehydes. The results as obtained in a t least duplicate runs in every case are summirized in Table I. 'I'AELB
In the high concentration of sulfuric acid usually employed in the Schmidt reaction only tarry materials were formed. Similarly treatment of styrene oxide with hydrazoic acid in the presence of thionyl chloride, zinc chloride and trichloroacetic acid gave no isolable product. With anhydrous stannic chloride a 17% yield of aniline and a low yield of a mixture of neutral nitrogen containing compounds, which were not separated or identified, were obtained. The reaction in aqueous dioxane of styrene oxide with sodium azide, however, gave a good yield of nitrogenous product, CsH,N30. This product, which will be the subject of a future communication, is either P-phenyl-/3-azidoethanol (I) or 5phenyl-5,B-dihydro-l,2,3,4-oxatriazine(11) as shown by its hydrogenolysis to 0-phenyl-&aminoethanol (111) in high yield.
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Formanilide
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H--N
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Yields are based on unrecovered aldehyde and include yields of hydrolysis products as well as of unhydrolyzed nitrile and amide. I n every case, the aniount of nitrogen evolved during the course of reaction was equal to or greater than that indicated stoichiometrically for the yield of proriurts reported.
Since the reactions of epoxides are in many respects similar to those of aldehydes, the reaction of hydrazoic acid with styrene oxide was studied in the hope that additional light might be shed on the niechanism of the reactions with aldehydes. 11) Abstracted from t h e Ph.D. thesis of Walter E. Conrad, July, 1051. A summary of this work was presented a t t h e X I I t h Internation:%l Congress of Pure a n d Applied Chemistry, Y e w York, Sept. i 0 -
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