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be eet ot ARN eg Mid, Cry 
ae” Be, 
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155 
: 0 incole late years ago, NG. Casmane: and A. nari): described a ketone 
¢ ~soHyeO: (ketocineole) showing a feeble smell of cineole. Recently, Cusmano’*) has 
“observed that this ketone, in the same manner as camphor, accelerates catalytically 
acceleration, discovered by Schulze’) and utilised on factory scale, was found to 
take place also with cyclohexanone, menthone, and tetrahydrocarvone. On the other 
3 and, the reaction does not pass off in presence of «-monobromo camphor, camphor 
‘into the molecule, e.g. by converting the sulphonic acid into the amide, or the quinone 
‘into its oxime. Camphor oxime and pernitroso camphor oxime act equally as acceler- 
_ ators. All the compounds mentioned dissolve in liquid sulphur dioxide. On distilling 
- off the sulphuryl dichloride, either the catalyst or its reaction-product is recovered; 
_ with ketocineole this is the identical chlorinated produ& as is obtained when chlorinat- 
_ ing in light petroleum solution. This compound, however, is not formed during the 
- formation of sulphuryl chloride, but only on the ee off the latter, lies by 
~ action of the boiling aie een | | | 
q Picks On page 129 of our Report for 1918, we pronane’: an: sydiaet of a 
- preliminary publication *) of Wallach on the conversion of menthone into pulegenone. 
Recently, the same author®) published a second paper on this reaction, from which © 
we gather. some details in order to supplement our former abstract. We then mentioned | 
- the fact that in Wallach’s opinion Cusmano’s formula for the monobromide of buchu 
camphor (m. p. 77.to 78°; according to Cusmano, 85°) is incorrect. Cusmano ascribes 
- formula I to the bromide and takes for granted that’ the formula for buchu camphor 
eis 2 the one put forward by Semmler (Il). Cusmano bases his view on the fact that 
ihe found the bromide, on treatment with alkali, to pass over into hydroxythymoquinone, 
_ and infers therefrom that in this reaction bromine is interchanged for hydroxyl with 
P simultaneous oxidation, the hydroaromatic compound formed primarily being converted 
_ into an aromatic one. Wallach was able to prove that the reaction proceeds differently, 
_ by succeeding in abstracting hydrogen bromide from the bromide on heating with 
_ pyridine, with formation of hydroxythymoquinone. Since this reaction passes off 
_ without the presence of water, it may be concluded that the formation of hydroxy- 
"the formation of sulphuryl chloride from sulphur dioxide and chlorine. The same 
_ sulphonic acid, or camphor quinone. Monochloro- or -bromoketocineole are likewise 
_ without effect, the latter, however, may be realised by introducing a positive radical 
_ thymoquinone from the monobromide, as primary reaction- product, is not effected by 
_ interchangement of bromine for hydroxyl, but that, for the first, hydrogen bromide is 
_ split off. Hence, the conclusion leading to the assumption of position 5 for the 
bromine atom of the monobromide was disproved. Wallach takes it for far more 
probable that on brominating the hydroxyketone the tertiary H-atom in position 4 is 
substituted by bromine, thus resulting in formula III for the monobromide. On the 
a 
a 
ate 
; 
_ other hand, it must be admitted that rearrangements may take pnt in the reaction, rae 
so that possibly a bromide of formula I is formed. 
_ The formation of the other monobromide m.p. 100 to 101° faibe mentioned in our 
_ former abstract) seems to depend largely on the temperature of the bromination, as 
to which Wallach gives exact details. It would lead us too far to reproduce them 
in full. On further bromination of this ‘monobromide, in glacial acetic acid solution, 
oe 
1) Gazz. chim. ital. 42% (1912), 1. 1; Chem. Zentralbl. 1912, 1. 1021; Report October 1912, 107. — %) Atti 
R. Acead. dei Lincei (5) 27, Il. (1918), 201; Chem. Zentralbl. 1919, Ill. 93. — 4) Journ. f. prakt. Chem. Il. 24 
(1881), 108. — *) Nachr. K. Ges. Wiss., Gottingen 1917, meeting of Oct. 26. —-.5) Liebig’s Annalen 418 (1919), 36. 
