The use of acetaldehyde and oxygen htead of peracetic acid as an oxidislng aqent. A simple preparation of iodoxybenzene.In our paper on the induced oxidation of iodobenzene during the oxidation of benzaldehyde in an atmosphere of oxygen I ) , we mentioned that B 6 e s e k e n and S c h n e i d e r investigated 4 ) the oxidation of iodobenzene by peracetic and perbenzoic acid. Using a solution of peracetic acid in acetic acid, they obtained iodosobenzene diacetate. When using, however, a solution of perbtnzoic acid in chloroform, iodoxybenzene was the oxidation product. In the oxidation of iodobenzene by a solution of peracetic acid in chloroform or by a solution of perbenzoic acid in acetic acid, mixtures of C,H,IO and C,H,IO, were observed.Our investigation 1 ) showed that under favourable conditions the inductor (benzaldehyde) and the acceptor (iodobenzene) fixed the same quantity of oxygen.The substance formed by the induced oxidation of iodobenzene dissolved in benzaldehyde was proved to be the dibenzoate of iodosobenzene. When using a solution of benzaldehyde and iodobenzene in acetone the oxidation-product appeared to be mainly the monobenzoate of iodosobenzene.W e now tried to use acetaldehyde as inductor. A solution of iodobenzene in acetaldehyde was exposed to the action of oxygen in a 1) W. P. l o r i s s e n and Miss A. C. B. D e k k i n g , Rec. trav.chim.57.829(1938).

The system ascorbic add-glucase-orygen compared with the system ascorbfc acid-arsenite-oxy gen.

This investigation is an attempt to use benzaldehyde and oxygen instead of perbenzoic acid as an oxidising agent. 1.In a series of papers 1) J. B o e s e k e n and several of his pupils have published the results of their researches on the oxidation of organic compounds by means of peracetic acid and perbenzoic acid.Especially those ohtained by the action of the latter substance drew our attention as one of u s * ) has studied some induced oxidations observed during the oxidation of benzaldehyde in an atmosphere of oxygen or air.Moreover, in collaboration with P. A. A. v a n d e r B e e k, he showed 3) that a solution of benzaldehyde in acetone (and some other solvents) produces, on oxidation in oxygen, perbenzoic acid in good yield (up to 63 %), especially in direct sunlight. In this connection the question arose whether some of the reactions observed by B o e s e k e n with perbenzoic acid could be obtained also by the action of oxidizing benzaldehyde. The oxidation of I ) J. B 6 e s e k e n and c:ollaborators: (1931); Chem. Weekblad 31, 166 (1934); and the dissertations of W. C. Smi t, C. v a n M e e u w e n (19.34). J. S t u u r m a n (1936) and J. D. J a c o b s (1936). 2, W. P. J o r i s s e n , Z. physik. Chem. 22, 34, 54 (1897); W. P. J o r i s s e n and W. E. R i n g e r , J. prakt. Chem. (2) 72, 173 (1905); W. P. J o r i s s e n and P. A. A. v a n d e r B e e k , Rec. trav. chim. 45, 245 (1926Rec. trav. chim. 45, 245 ( ), 46, 42 (1927Rec. trav. chim. 45, 245 ( ), t9, 138 (1930; P. A. A. v a n d e r B e e k . Ibid. 47, 301 (1928); A. H. B e l i n f a n t e , dissertation Leiden 1933. W. P. J o r i s s e n and P. A. A. v a n d e r B e e k.. Rec. trav. chim. 45, 245 (1926); P. A. A. v a n d e r B e e k, dissertation Leiden 1926, Rec. trav. chim. 47, 286 (1928.

In the oxidation of xanthine and of uric acid in 'ilkaline solution at 37' (or 40 ) by free oxygen the oxidation of an arsenite sohtion is induced. Equipartition of the oxygen is thereby observed.1. Uric acid is formed in mammals mainly by the oxidation of purine bases. In birds and reptiles uric acid is also the final product of protein metabolism. T h e liver and kidneys of birds are able to form uric acid by fermentation: the nitrogen of amino acids serves as source of nitrogen. Xanthine or hypoxanthine are probably formed first, and these then are oxidized in the kidney to uric acid.T h e uric acid formed is excreted by birds and reptiles as well as by human beings and certain kinds of apes, while most mammals oxidize uric acid to allantoin by means of the ferment uricase. In fishes and amphibians the allantoin is further broken down and the final products are urea and ammonia 1 ) .K e i I i n and H a r t r e e 2 ) ) . who studied the catalysis of the oxidation of uric acid to allantoin and carbon dioxide by uricase. also investigated the oxidation of alcohol induced by this reaction 3). In their investigation they also included the coupled oxidation of alanine and alcohol when amino acid oxidase (and catalase) were present. and that of hypoxanthine and alcohol in the presence of xanthine oxidase and catalase. Miss T h u r 1 o w 4 ) has already mentioned the formation of peroxide in the oxidation of hypoxanthine and of xanthine in the presence of xanthine oxidase.In the experiment of K e i I i n and H a r t r e e the alcohol was found to take up about as much oxygen as the uric acid, the alanine or the hypoxanthine.This result is in agreement with that obtained in the case of a number of other coupled oxidations 5 ) . namely that the accepter binds the same amount of oxygen as the inductor. These oxidations. however, took place in the absence of an oxydase 6 ) .In these investigations use was made several times of an arsenite solution 2.1) E. S t r a n s k y . Biochem. Z . 266, 287 (1933) 111 Teil (1931Teil ( -1938