— 195 — 



which is to be regarded as a derivative of the tautomeric peroxide of 

 hydrogen H 2 0:0. As it was a matter of interest to determine whether 

 other fatty aldehydes behaved in an analogous manner towards ozone, 

 Harries and Koetschau 1 ) have examined a series of these bodies. From 

 the results of their investigation, published some time ago, it appears that 

 the aliphatic aldehydes, with the exception of formaldehyde, are converted 

 into the peroxide-like compound mentioned above. They prepared peroxides 

 of heptylic aldehyde (df| 0,9081 ; n D8Q 1,42876), peroxide of octylic aldehyde' 2 ), 

 (m. p. — 4° to +3°), peroxide of nonylic aldehyde (m. p. about +6°; 

 d§§ 0,8906; n D2] o 1,43668), peroxide of dodecylic aldehyde and peroxide of 

 isovaleric aldehyde (dffg 0,9462; n D23Q 1,40826). 



Harries and Turk 3 ) have also investigated more closely the perozonide 

 of methylheptenone, which had already been prepared previously by 

 Langheld 4 ). The results of their examination showed that when peroxide 

 of methylheptenone is split up with water, acetone hyperoxide, acetone, 

 methylphenyldihydropyridazine and lsevulic acid are formed. 



o- Vanillin. When ordinary vanillin is prepared from guaiacol by 

 Tiemann-Reimers method, o-hydroxy-m-methoxybenzaldehyde or m-methoxy- 

 salicylic aldehyde is formed as a by-product. Francis Nolting 5 ) has prepared 

 the last-named body in pure crystalline form from the guaiacol-free residues 

 of vanillin -manufacture by simple distillation by steam. The abstract 

 at our disposal gives no particulars of the odoriferous properties of the 

 body. From water it was obtained in bright yellow needles, and from 

 organic solvents in intense yellow crystals, melting at 45,5°, b. p. 265 to 

 266°. In acetic acid solution it dyed wool a golden-yellow, and silk a 

 bright yellow colour. o-Vanillin, as the author calls the substance, yielded, 

 in its dual capacity as phenol and aldehyde, a long series of derivatives, 

 Such as ethers, esters, bisulphite-compound, oxime, hydrazone, aldazines, 

 azimethines (Schiffs bases). When condensed with dimethylaniline in the 

 presence of chloride of zinc, o-vanillin and its methylether, o-veratric 

 aldehyde, yielded triphenylmethane dyes. Nolting further succeeded in 

 preparing from the aldehyde by condensation with acetic anhydride and 

 acetate of potassium, o-methoxycoumarin, which was obtained in the form 

 of odourless white needles, volatile with steam, m. p. 89°. Pauly and 

 Lockemann 6 ) have split up o-vanillin by Stormer's method into o-proto- 

 catechuic aldehyde, which formed sulphur -coloured crystals, melting 

 at 108°. When treated with phosgene, the barium salt of this aldehyde 



!) Liebigs Annalen 374 (1910), 321. 



2 ) From octylic aldehyde supplied by us. 



3 ) Ibidem 338. 



4 ) Loc. cit. 



5 ) Annal. de Chim. et Phys. VIII. 19 (1910), 476; quoted from Chem. Zentralbl. 1910, 1. 1880. 

 «) Berl. Berichte 43 (1910), 1813. 



13* 



