89 A-90 A.] 



ASARONE 



165 



into its methyl ether, and then reduced 

 to o-anisidine (Miilhauser, Ann. 207, 

 239). The latter, on oxidation with 

 sulphuric acid and potassium dichro- 

 mate, gives methoxyquinone (Ibid. 25 1 ; 

 Will, Ber. 21, 605), and this by reduc- 

 tion methoxyquinol (Will, loc. cit. 606). 

 The latter, on further methylation with 

 methyl iodide and potassium hydroxide, 

 yields the i : 2 : 4-trimethoxybenzene 

 (Will). By the action of hydrogen 

 cyanide on the latter in conjunction 

 with hydrogen chloride in presence of 

 aluminium chloride the 2:4: 5-trimeth- 

 oxybenzaldehyde = asaryl aldehyde [125] 

 is formed (Gattermann and Eggers, Ber. 

 32, 289), and this, on heating with 

 propionic anhydride and sodium pro- 

 pionate at 150, gives asarone (Ibid. 

 290). 



[B.] Eesorcinol [70] may replace 

 phenol in the above synthesis. Diazo- 

 tised aniline is combined with resor- 

 cinol, the azo-compound methylated by 

 heating with potassium hydroxide and 

 methyl iodide (Bechold, Ber. 22, 2375), 

 and the dimethyl ether reduced to i : 3- 

 methoxy-4-aminobenzene. The latter, 

 on oxidation with sulphuric acid and 

 sodium dichromate, gives methoxyqui- 

 none (Ibid. 2381), which can be reduced, 

 methylated, and treated as under A. 



[C.] Quinol [7l] may replace phenol 

 in this synthesis since, on fusion with 

 sodium hydroxide, it gives I : 2 : 4-tri- 

 hydroxybenzene (hydroxyquinol [85]) 

 (Barth and Schreder, Monats. 4, 176; 

 5, 59); an( i this can be converted into 

 the trimethyl ether by methylation, and 

 then treated as above under A. 



[D.] Quinone [142] gives hydroxy- 

 quinol triacetate on treatment with 

 acetic anhydride and a little sulphuric 

 acid (Thiele, Ber. 31, 1247 : see a ^ so 

 [85]). The triacetate hydrolysesto the 

 trihydroxy-compound, which -can be 

 treated as above. 



[E.] From asaryl aldehyde [125] and 

 propionic acid [Vol. II] by heating the 

 aldehyde with propionic anhydride and 

 sodium propionate (Gattermann and 

 Eggers, as under A above). 



90. a-Hydrojuglone ; 



1:4: 5-Triliyclroxyiiaphthaleiie ; 



1:4: 8-Naplithalenetriol. 



HO HO 



HO 



NATURAL SOURCE. 



In all green parts of the walnut 

 tree, Juglans regia (Mylius, Ber. 17, 



2411; 18,475; 2567). 



SYNTHETICAL PROCESSES. 



Syntheses of Naphthalene. 



[A.] From benzene through toluene 

 and benzyl chloride (see under benzyl 

 alcohol [54 ; A, &c.]). The latter, when 

 mixed with allyl iodide (see under iso- 

 butyl alcohol [18; D]) and treated in 

 ethereal solution with sodium, gives 

 phenylbutylene (Aronheim, Ann. 171, 

 225), the dibromide (Ibid. 229) of which 

 yields naphthalene on passing the vapour 

 over hot lime (Ibid. 233). 



From benzyl chloride and isopropyl 

 alcohol [16] by acting with sodium on 

 a mixture of isopropyl iodide and ben- 

 zyl chloride in ether so as to form 

 isobutylbenzene (Kohler and Aronheim, 

 Ber. 8, 509). The latter gives naph- 

 thalene on passing the vapour over 

 heated lead oxide (Wreden and Snato- 

 wicz, Ber. 9, 1606). 



Benzene and isobutyl alcohol [18] also 

 give isobutylbenzene by the action of 

 sodium on brombenzene and isobutyl 

 bromide or iodide in ether or benzene, 

 (Eiess, Ber. 3, 779 ; Wredin and Snato- 

 wicz, loc. cit.}, or directly by heating 

 benzene with the alcohol and zinc chloride 

 at 300 (Goldschmidt, Ber. 15, 1066; 

 1425). Also by the action of aluminium 

 chloride on a mixture of benzene and 

 isobutyl chloride (Gossin, Bull. Soc. [2] 

 41, 446). 



From toluene, malonic acid [Vol. II], 

 and alcohol [14]. Malonic acid is con- 

 verted into its diethyl ester and the 



