212 



AROMATIC ALDEHYDES AND KETONES [115 A-116. 



forms a compound with chromium oxy- 

 chloride which gives the above aldehyde 

 on decomposition by water (Etard, Ann. 

 Chim. [5] 22, 254 : according to later 

 experiments by v. Miller and Rohde, 

 Ber. 23^ 1070, this process gives benzoic 

 and not hydrocinnamic aldehyde). 



NOTE : Propyl chloride and benzene give 

 also isopropylbenzene = cumene by the action 

 of aluminium chloride unless the temperature 

 is kept below o (Konowaloff, Journ. Russ. Soc. 

 27, 457)- 



[B.] From benzoic aldehyde [114] and 

 ethyl alcohol [14] through ethylphenyl 

 carbinol by the interaction of the alde- 

 hyde and magnesium ethiodide, the 

 chloride by the action of phosphorus 

 pentachloride on the alcohol, and pro- 

 penylbenzene by heating the chloride 

 with pyridine. Propenylbenzene gives 

 propylbenzene on reduction with sodium 

 in alcoholic solution (Klages, Ber. 36, 

 621 : see also Wagner, Journ. Russ. Soc. 

 16, 324). 



NOTE : Generators of propenylbenzene are : 

 bromhydroxyphenylcrotonic acid (Perkin, 

 Journ. Ch. Soc. 32, 660) ; a-methyl--phenyl- 

 hydroxypropionic acid (W. H. Perkin, junr., 

 and Sfcenhouse, Trans. Ch. Soc. 59, 1010) ; 

 niethylbenzyl ketone or ethylphenyl ketone or 

 the chlorides from the corresponding secon- 

 dary alcohols (Errera, Gazz. 14, 504; 16, 318) ; 

 phenopropyltrimethylammonium hydroxide 

 (Senfter and Tafel, Ber. 27, 2312"; brompro- 

 piophenone from brompropionic acid and ben- 

 zene through a-ehlor-j8-brompropenylbenzene 

 (Kunkell and Dettmar, Ber. 36, 771 : compare 

 with respect to this process Klages, Ber. 36, 

 2 57 2 )- 



[C.] From glycerol [48] through allyl 

 bromide (see under n-propyl alcohol 

 [15 ; E]) and benzene, a mixture of the 

 bromide and hydrocarbon giving propyl- 

 benzene among other products when 

 heated with zinc dust (Shukowski, 

 Journ. Russ. Soc. 27, 297). 



[D.] From quinoline[ Vol. II], propyl- 

 benzene being among the products of 

 reduction by hydriodic acid and phos- 

 phorus at 300-310 (Bamberger and 

 Williamson, Ber. 27, 1477)- 



[E.] From cinnamic aldehyde [123]. 

 The hydrochloride of a formimino-ether 

 (prepared by the interaction of hydrogen 

 cyanide [172] and an alcohol in presence 

 of hydrogen chloride ; Pinner, ( Die 



Imidoaether/ 1892) condenses with the 

 aldehyde to form an acetal (Claisen, 

 Ber. 31, 1016). The latter, after reduc- 

 tion by sodium in alcohol, is decomposed 

 into hydrocinnamic aldehyde on heating 

 with dilute sulphuric acid (Fischer and 

 Hoffa, Ber. 31, 1991). The dimethyl 

 acetal is also formed from cinnamic 

 aldehyde and methyl alcohol by the 

 condensing action of hydrogen chloride 

 (F. and H. loc. cif. 1990). 



[F.] From hydrocinnamic and formic 

 acids [Vol. II] by distilling a mixture 

 of the calcium salts (v. Miller, Rohde, 

 and Gerdeissen, Ber. 23, 1080 : see also 

 Dollfuss, Ber. 26, 1971). 



116. Cumic Aldehyde; Cuminol; 

 Fara-isopropylphenal ; Cuminal ; 



4-Methoetliylplieiienietliylal. 



CHO 



CH(CH 3 ) a 



NATURAL SOURCES. 



Occurs (with cymene) in Roman oil 

 of cumin from Cuminum cyminum (Ger- 

 hardt and Cahours, Ann. 38, 70 ; Ann. 

 Chim. [3] 1, 60 ; Bertagnini, Ann. 85, 

 275 ; Kraut, Ann. 92, 66), and in oil 

 of water-hemlock from Cicuta virosa 

 (Trapp, Journ. pr. Ch. 74, 428 ; Arch. 

 Pharm. 231, 212; Ann. 108, 3X6). 



Said to occur also in oil of thyme 

 from Thymus vulgaris and T. serpyllum, 

 in oil of true bishop's weed from 

 Ptycholis ajowan, in oil of pepperwort 

 from Satureia hortensis, and in oils of 

 Eucalyptus globulus, ginger, nutmeg, 

 sage, and citron (Sawer's ' Odoro- 

 graphia,' Vol. II, p. 140 : authorities 

 not given). 



Cuminal is contained in the oils of 

 Eucalyptus heemastoma (SchimmeFs Ber. 

 April, 1888), E. odorata (Ibid. April, 

 1889), E. oleosa (Gildemeister and 

 Hoffmann, p. 695), E. pnpulifera 

 (SchimmeFs Ber. April, 1893), (?) E. 



