166 



AROMATIC ALCOHOLS AND PHENOLS 



[90 A. 



latter into chlormalonic ester by chlori- 

 nation (Conrad and Bischoff:, Ann. 209, 

 219). By the action of chlormalonic 

 ester on sodiomalonic ester in alcoholic 

 solution the tetra-ethyl ester of s- 

 ethanetetracarboxylic (butanediacid-2 : 

 3-dimethylic or acetylenetetracarboxylic) 

 acid is formed (Hid. 214, 68 ; Ber. 13, 

 601 ; 21, 3087 ; Bischoff and Rach, 

 Ber. 17, 3785). 



The same tetracarboxylic ester is also 

 formed by the action of iodine on ma- 

 Ionic ester in presence of sodium eth- 

 oxide (Bischoff, Ber. 16, 1046; Bischoff 

 and Rach, Ber. 17, 3781), by the elec- 

 trolysis of an alcoholic solution of sodio- 

 malonic diethyl ester (Mulliken, Am. 

 Ch. Journ. 15, 523; Weems, Ibid. 16, 

 569), by the interaction of acetylene 

 tetrabromide, malonic ester, and sodium 

 ethoxide (Crossley, Proc. Ch. Soc. 14, 

 348), and also from nitromalonic ester 

 (see under hydrogen cyanide [172 ; AA]) 

 through ethanedinitro-tetracarboxylic 

 ester by electrolysis : the dinitro-ester 

 gives the tetracarboxylic ester by reduc- 

 tion (Ulpiani and Gasparini, Gazz. 32, 



235). 



Toluene can be converted into o- 

 xylene (see under m-cresol [62 ; A]) by 

 methylation, and the latter into o-xylyl- 

 ene dibromide (i 1 : 2 1 -dibromxylene) by 

 bromination (Radziszewski and Wispek, 

 Ber. 18, 1381; Schramm, Ibid. 1379; 

 W. H. Perkin, junr., Trans. Ch. Soc. 

 53, 5). The xylylene dibromide and 

 ethanetetracarboxylic ester react when 

 heated in alcoholic solution in the pre- 

 sence of sodium ethoxide with the for- 

 mation of 1:2:3: 4-tetrahydronaph- 

 thalene-2 : 2 : 3 : 3 -tetracarboxylic tetra- 

 ethyl ester (Baeyer and W. H. Perkin, 

 junr., Ber. 17, 450; W. H. P., junr., 

 Trans. Ch. Soc. 53, ia), and this on 

 hydrolysis yields the free acid which, on 

 heating at 185, gives the anhydride of 

 tetrahydronaphthalene-dicarboxylicacid 

 (B. and P. loc. cit.}. The latter, when 

 passed through a red-hot tube, or when 

 the silver salt of the free acid is heated, 

 yields naphthalene (Ibid. 451). 



Or sodio-chlormalonic ester and o- 

 xylylene dibromide may be heated in 

 alcoholic solution so as to form o-xylyl- 

 enedichlordimalonic tetra-ethyl ester 



(Ibid. 452), and this, by treatment with 

 zinc dust and acetic acid, gives o-xylyl- 

 enedimalonic tetra-ethyl ester (Ibid, and 

 W. H. Perkin, junr., Trans. Ch. Soc. 

 53, 1 6). By the action of iodine (ethe- 

 real solution) on the sodium derivative 

 of the latter ester the tetrahydronaph- 

 thalene derivative is formed, and can be 

 treated as above (Baeyer and W. H. 

 Perkin, junr., Ber. 17, 452). 



NOTE : The ethanetetracarboxylic ester re- 

 quired for this synthesis of naphthalene can 

 also be obtained from the amyl alcohol of fusel 

 oil [22] by converting the latter into amylene 

 (see under acetone [106 ; E]) and its dibromide. 

 The latter on heating with sodiomalonic ester 

 gives (with trimethylethylene) ethanetetra- 

 carboxylic ester (Ipatieff. Journ. Russ. Soc. 30, 

 391). Alkylene dibromidesof the general form. 

 K 2 CBr. CH 2 . CH 2 Br give the tetracarboxylic 

 acid as a by-product by the action of sodio- 

 malonic ester (Ibid. 31, 349 ; also Ipatieff and 

 Swiderski, Ibid. 33, 532 ; Ipatieff, Ibid. 34, 

 350- 



The conversion (partial) of benzene 

 into naphthalene may also be effected 

 through nitrobenzene, aniline, dimethyl- 

 aniline by methylation, and the action 

 of bromine on the latter at 110-120 

 (Brunner and Brandenburg, Ber. 11, 

 698). 



Naphthalene is among the aromatic 

 hydrocarbons formed when the copper 

 compound of acetylene [l ; A] is dis- 

 tilled with zinc dust (Erdmann and 

 Kothner, Zeit. anorg. Ch. 18, 48). 

 Naphthalene is formed with other pro- 

 ducts by pyrogenic synthesis from : 



Alcohol (Reichenbach, Berz. Jahres- 

 ber. 12, 307) ; methane ; acetic acid ; 

 toluene; xylene; pseudocumene ; ethyl- 

 ene and benzene ; ethylene and styrene ; 

 ethylene and anthracene (Berthelot, 

 Bull. Soc. [2] 6, 272 ; 279 ; Ferko, 

 Ber. 20, 660); ethylene (Norton and 

 Noyes, Am. Ch. Journ. 8, 362) ; acetyl- 

 ene or acetylene and benzene (Berthelot, 

 Comp. Rend. 62, 905; 93,613; Bull. 

 Soc. [2] 6, 268; 7, 2l8; 274; 303; 

 9, 456) ; ethylene and diphenyl (Barbier, 

 Comp. Rend. 79, 121); heptane; 

 octane; n-hexyl alcohol (Worstall and 

 Burwell, Am. Ch. Journ. 19, 815); iso- 

 butylene (Noyes; Beilstein, I, 115). 



Naphthalene is formed from certain 

 metallic carbides, e. g. of barium, by 



