254 



165. Secondary Butyl Isothiocyanate 

 or Thiocarbimicle ; 

 Oil of Spoonwort. 



CH 3 .CH 2 .CH(CH 3 ).NCS 



NATURAL SOURCE. 



In oil of spoonwort or scurvy-grass, 

 Cochlearia officinalis (Hofmann, Ber. 2, 

 1 02 ; 7, 508 ; Gadamer, Arch. Pharm. 

 237, 92). According 1 to Gadamar (loc. 

 cit.} it probably exists as glucoside in 

 the plant. 



SYNTHETICAL PROCESSES. 



[A.] From n-butyl alcohol [17] and 

 carbon disulphide [160]. The alcohol 

 is converted into n-butylene through 

 n-butyl iodide (Linnemann, Ann. 161, 

 196) and the action of alcoholic potash 

 on the latter (Lieben and Rossi, Ann. 

 158, 164 ; Saytzeff, Journ. pr. Ch. [2] 

 3, 88 ; Grabowsky and Saytzeff, Ann. 

 179, 330). n-Butylene combines with 

 hydrogen iodide to form 2-iodobutane 

 = secondary butyl iodide (Wurtz, Ann. 

 152, 23 ; Saytzeff, Ber. 3, 870). The 

 latter, by the action of ammonia, gives 

 the amine = 2-aminobutane (Hofmann, 

 Ber. 7, 513), and this on combination 

 with carbon disulphide in alcoholic or 

 ethereal solution, precipitation of the 

 product [di-(sec.)-butyldithiocarbamate] 

 with mercuric chloride, and decomposi- 

 tion of the mercury compound by boiling 

 with water yields the isothiocyanate 

 (Hofmann, Ber. 7, 512). 



[B.] Isobutyl alcohol [18] by the action 

 of hot zinc chloride gives a mixture of 

 two butylenes, of which one is pseudo- 

 butylene = symmetrical dimethylethyl- 

 ene (Nevole, Bull. Soc. [2] 24, 122 ; Le 

 Bel and Greene, Am. Ch. Journ. 2, 23 ; 

 Bull. Soc. [2] 29, 306 ; Faworsky and 

 Desbout, Journ. pr. Ch. [2] 42, 152 ; 

 J. Wislicenus and Schmidt, Ann. 313, 

 210 : see also Nef, Ann. 318, 28). 

 The latter combines with hydrogen 

 iodide to form secondary butyl iodide, 

 which can be converted into the amine 

 and treated with carbon disulphide [160], 

 &c., as above under A. 



Isobutyl alcohol also gives pseudo- 



[165-D. 



butylene' (with isobutylene) by the 

 action of sulphuric acid (Konowaloff, 

 Bull. Soc. [2] 34, 333 ; Puchot, Ann. 

 China. [5] 28, 508), or by pyrogenic 

 contact decomposition by plumbago 

 crucible material (Ipatieff, Ber. 35, 

 1061). 



Isobutyl chloride gives all three 

 butylenes on pyrogenic decomposition 

 by passing over heated lime (Nef, Ann. 

 318, 22). 



NOTE : For conversion of psettdobutylene 

 into methylethyl ketone see under methylacetyl 

 carbinol [44 ; D]. The ketone is convertible 

 into secondary butyl alcohol and amine as 

 below under K. 



[C.] From methyl alcohol [13], glycerol 

 [48], and carbon disulphide [160]. 

 Methyl alcohol is converted into methyl 

 iodide, and glycerol into allyl iodide 

 (see under isobutyl alcohol [18; D]). 

 A mixture of the two iodides on 

 treatment with sodium gives (by iso- 

 meric transformation?) pseudobutylene 

 (Wurtz, Bull. Soc. [2] 8, 265 ; Ann. 

 144, 235; Grosheintz, Bull. Soc. [2] 

 29, 201), which can be converted into 

 2-iodobutane, &c., as above. 



[D.] From acetic aldehyde [92] and 

 carbon disulphide [160]. Aldehyde is 

 convertible by the action of sulphuretted 

 hydrogen into a solid trithioaldehyde, 

 C 6 H 12 S 3 (Weidenbusch, Ann. 66, 158 ; 

 Pinner, Ber. 4, 258 ; Klinger, Ber. 9, 

 1893; 11, 1024; Bottinger, Ber. 11, 

 2205; Friedel and Crafts, Ann. 124, 

 114; Baumann and Fromm, Ber. 22, 

 2602; 24, 1464; Fromm, Ber. 32, 

 2650), and' this gives pseudobutylene 

 on heating with copper (Eltekoff, Ber. 

 10, 1904). 



Or from aldehyde, ethyl alcohol [14], 

 and carbon disulphide. Zinc ethyl and 

 aldehyde combine to form a compound, 

 which is decomposed by water with the 

 formation of 2-butanol (Wagner, Ann. 

 181, 261). Subsequent steps as below 

 under G. 



Or aldehyde combines with hydrogen 

 chloride to form ethylidene oxychloride 

 = i : I 1 -dichlorether (Lieben, Comp. 

 Rend. 46, 662 ; Ann. 106, 336 ; Kessel, 

 Ann. 175,44; Geuther, Ann. 218, 16), 

 which by the action of zinc ethyl gives 

 secondary butyl ether. The latter on 



