92 A-C.] 



ACETIC ALDEHYDE 



175 



Erdmann and Kothner, Zeit. anorg. Ch. 

 18, 48), or by the action of mercuric 

 bromide on acetylene and water (Kut- 

 scheroff, Ber. 14, 1540) ; also by com- 

 bining- acetylene with mercuric chloride 

 and decomposing- the compound with 

 dilute hydrochloric acid (Ibid. 17, 13; 

 Kriig-er and Piickert, Ch. Ind. 1895, 

 p. 454 : see also T ravers and Plimpton, 

 Trans. Ch. Soc. 65, 265). 



Acetylene also combines with mer- 

 curic nitrate to form a compound which 

 readily gives aldehyde on decomposition 

 (Kothner, Inaug-. Diss. Halle, 1896; 

 Erdmann and Kothner, loc. cit. ; Ber. 

 81, 3475 ') K. A. Hofmann, Ber. 31, 

 3212; 2783). Acetylene forms a 

 compound with mercuric acetate which 

 decomposes on heating- with acids 

 with the formation of aldehyde (Bur- 

 kard and Travers, Trans. Ch. Soc. 81, 

 1271). 



Aldehyde is formed when acetylene 

 is passed through boiling phosphoric 

 add (1-15 sp. gr.) or sulphuric acid (30 

 per cent.) containing mercuric oxide in 

 suspension (Erdmann and Kothner, 

 loc. cit.}. 



Aldehyde is among the products of 

 oxidation of acetylene by hydrogen 

 peroxide in presence of ferrous sulphate 

 (Cross, Bevan, and Heiberg, Ber. 33, 

 2015). 



Acetylene combines with water to 

 form aldehyde above 300 (Desgrez, 

 Ann. China. [7] 3, 216). 



Or from ethylene by heating with 

 carbon dioxide at 400 (Schiitzenberger, 

 Bull. Soc. [2] 31, 482) ; or from ethyl- 

 ene dibromide and water at 150-160 

 (Carius, Ann. 131, 172), or from the 

 dibromide through vinyl bromide and 

 the action of mercuric acetate on the 

 latter (Saytzeff, Zeit. [2] 3, 675 ; Linne- 

 mann, Ann. 143, 347). 



Also from ethylene through glycol [45 ]. 

 The latter gives aldehyde when heated 

 with water to 210 (Nevole, Bull. Soc. 

 [2] 25, 289), or with zinc chloride 

 (Wurtz, Ann. 108, 915 : see also Lie- 

 ben, Monats. 23, 60). 



Or ethylene can be combined with 

 hypoehlorous acid to form chlorethyl 

 alcohol = glycol chlorhydrin (Carius, 

 Ann. 126, 197), which on treatment with 



potassium iodide gives glycol iodhydrin 

 (Butleroff and Ossokin, Ann. 144, 42). 

 The latter, on heating with lead hy- 

 droxide, gives aldehyde quantitatively 

 (Charon and Paix-Seailles, Comp. Rend. 

 130, 1407). 



Glycol chlorhydrin gives aldehyde 

 among the products of decomposition 

 by heating in contact with lead or zinc 

 oxide. (Kaschirsky, Ber. 10, 1 104), or 

 (in small quantity) by heating with 

 water (Krassusky, Journ. Russ. Soc. 34, 

 287). Or the chlorhydrin, on treatment 

 with potash, gives ethylene oxide 

 (Wurtz, Ann. Chim. [3] 69, 317 ; Ann. 

 110, 125; Demole, Ann. 173, 125). 

 The latter yields aldehyde more readily 

 than the glycol when heated with zinc 

 chloride (Krassusky, loc. cit. 537). 



According to Berthelot, aldehyde is 

 formed by the oxidation of ethylene 

 with chromic acid (Comp. Rend. 68, 



334)- 



The ' ethylenic nitrate ' formed by the 

 combination of ethylene with nitric an- 

 hydride gives aldehyde on reduction 

 (Demjanoff, Ch. Centr. 1899, 1, 1064). 



[B.] Methane [l] and carbon mon- 

 oxide give aldehyde under the influence 

 of the silent electric discharge (Lo- 

 sanitsch and Jovitschitsch, Ber. 30, 



137)- 



Ethane and carbon monoxide also give 

 aldehyde by this method (De Hemp- 

 tinne, Bull. Acad. Roy. Belg. [3] 34, 

 269). 



Or from ethane and air by passing 

 over hot copper or asbestos, &c. (Glock, 

 Germ. Pat. 109015 of 1899; Ch. 

 Centr. 1900, 2, 304). 



NOTE: All generators of ethane (see under 

 ethyl alcohol [14 ; A ; D, &c.]) thus become 

 generators of aldehyde. 



[C.] From ethyl alcohol [14] by oxida- 

 tion (Dobereiner, Gmelin's ' Handbuch 

 d. org. Ch.' IV, 556 ; 585 ; 61 1 ; Liebig, 

 Ann. 14, 133 ; W. and R. Rodgers, 

 Journ. pr. Ch. 40, 240 ; Stadeler, Ibid. 

 76, 54 : for conditions determining the 

 electrolytic oxidation of alcohol to alde- 

 hyde see Dony-Henault, Zeit. Elektroch. 



e> 533)- 



Or from ethyl alcohol through its 



