136 



AROMATIC ALCOHOLS AND PHENOLS [66-67 B. 



stituents of oil of camphor (Sugiyama ; 

 SchimmeFs Ber. Oct. 1903; Ch. Centr. 

 1903, 2, 1307). 



SYNTHETICAL PROCESSES. 



[A.] From cymene [6] by sulphona- 

 tion (Gerhard t and Cahours, Ann. Chim. 

 [3] 1, 1 06; Delalande, Ibid. 368; 

 Miiller, Ber. 2, 1 30 ; Jacobsen, Ber. 

 11, 1060; Claus and Cratz, Ber. 13, 

 901; 14, 2141; Spica, Ber. 14, 653; 

 Gazz. 11, 201 ; Sieveking, Ann. 1O6, 

 260 ; Beilstein, Ann. 170, 287 ; Paterno, 

 Ber. 7, 591; Gazz. 3, 544; Kraut, 

 Ann. 192, 226; Baur, Ann. 220, 18), 

 and potash fusion of the a-(2)-sulphonic 

 acid thus formed (Pott, Ber. 2, 121 ; 

 H. Miiller, Ibid. 1 30 ; Jacobsen, Ber. 

 11, 1060). Cymene on nitration gives 

 2-nitrocymene (CH 3 = i) (Barlow, Ann. 

 98, 245 ; Landolph, Ber. 6, 937 ; 

 Fittica, Ann. 172, 314 ; Schumoff, 

 Journ. Russ. Soc. 19, 119; Widman, 

 Ber. 19, 584 ; Sbderbaum and Widman, 

 Ber. 21, 2126), and 2-aminocymene by 

 reduction (Soderbaum and Widman, 

 lac. cit. 2127). The cymidine thus 

 formed yields carvacrol by the diazo- 

 method (Semmler, Ber. 25, 3353)- 



[B.] Carvone [127] on heating with 

 acids or alkalis gives carvacrol (Volckel, 

 Ann. 85, 246; Kekule and Fleischer, 

 Ber. 6, 1088; Lustig, Ber. 19, 12; 

 Reychler, Bull. Soc. [3] 7, 32 ; Tiemann, 

 Ber. 32, 109). With formic acid the 

 yield is quantitative (Klages, Ber. 32, 

 1516). 



67. Thymol; Metacymophenol ; 



5-Methyl-2-Isopropylphenol ; 

 1 : 4-Metliylmethoetliyl-3-Fheiiol. 



CH 3 



,'OH 

 CH 3 . CH . CH 3 



NATURAL SOURCES. 



In oil of thyme from T/iymus vulgaris 

 (Doveri, Ann. Chim. [3] 20, 174; 

 Ann. 64, 374 : Lallemand, Comp. Rend. 

 37, 498 ; Ann. Chim. [3] 49, 148 ; 

 Ann. 102, 119) and T.serpyllum (Jahns, 



Ber. 15, 819; Arch. Pharm. 216, 277); 

 in oil from the seeds of bishop's weed, 

 Ptycliotis ajowan (Haines, Journ. Ch. 

 Soc. 8, 289; Stenhouse, Ann. 93, 269; 

 98,309; H. Miiller, Ber. 2, 130); in oil of 

 American horse-mint, Monarda punctata 

 (Arppe, Ann. 58, 41 ; SchimmePs Ber. 

 Oct. 1885; Schumann and Kremers, 

 Ch. Centr. 1897, 2 ; 4 2 ; Pharm. Rev. 

 1896, i); and in oil of Oswego tea 

 from Monarda didyma (Fliickiger, Arch. 

 Pharm. 212, 488). 



Menthol [4l] or peppermint camphor, 

 which occurs in the oil of Mentka pipe- 

 rita and other species of Mentha, is a 

 hexahydrothymol. The phenols present 

 in the oil of wild bergamot from Mo- 

 narda fistulosa contain less than 2 per 

 cent, of thymol (Kremers, Ch. Centr. 

 1899, 2, 126; Pharm. Arch. 2, 73). 



Thymol occurs in the N. American 

 oil of Cunila mariana (Millemann, Am. 

 Journ. Pharm. 38, 495 ; SchimmeFs 

 Ber. Oct. 1893), and (possibly) in the oil 

 of the N. American wild mint, Mentha 

 canadenxis (Gage, Pharm. Rev. 16, 412). 



The oil from the Japanese Mosla 

 japonica contains 44 per cent, thymol 

 (Shimoyama ; see Gildemeister and 

 Hoffmann, p. 861). 



Oil from the Algerian Origanum flori- 

 lundum = 0. clnereum contains thymol 

 (Battandier, Journ. Pharm. 16, 536 ; 

 Journ. Soc. Ch. Ind. 21, 1551). 



SYNTHETICAL PROCESSES. 



[A.] From cumic aldehyde [116] by 

 nitration, conversion of the nitro-deriv- 

 ative into nitrocymylidene chloride 

 (C 6 H 3 .CHC1 2 .N0 2 .C 3 H 7 =1:3:4) 

 by the action of phosphorus penta- 

 chloride, reduction to the corresponding 

 3-aminocymene by zinc and hydro- 

 chloric acid, and conversion into thymol 

 by the diazo-method (Widman, Ber. 15, 

 1 66). 



[B.] From menthone [129] through 

 the dibromo-derivative, the latter giving 

 thymol on heating with quinoline 

 (Beckmann and Eickelberg, Ber. 29, 

 418 : see also Oddo, Gazz. 27, 112). 



Or menthone gives, among the pro- 

 ducts of bromination, pentabromdehydro- 

 thymol,and this yields thymol by reduc- 



