165 D-M.] SECONDARY BUTYL ISOTHIOCYANATE 



255 



heating with hydriodic acid at 130 

 yields 2-iodobutane (Kessel, loc. cit.). 



[E.] From angelic or tiglic acid 

 [Vol. II] and carbon disulphide [160] 

 through brom-methylethylacetic acid = 

 3-brombutane-2-carboxylic acid by com- 

 bination of either of the isomeric acids 

 with hydrogen bromide (Pagenstecher, 

 Ann. 195, 109). Pseudobutylene is 

 among the products of decomposition 

 of the bromo-acid by alkali (Ibid. 113). 



Or the acids can be combined with 

 hydrogen iodide (Schmidt, Ann. 208, 

 254 ; J. Wislicenus, Talbot, and Henze, 

 Ann. 313, 207) ; the products give the 

 stereo-isomeric pseudobutylenes on treat- 

 ment with alkali (W. T. and H. loc. cit. : 

 see also Ch. Centr. 1897, 2, 261). 



[P.] From ethyl alcohol [14] and 

 carbon disulphide [160]. The alcohol 

 is converted into ether, and the latter 

 into i : 2-dichlorether (Malaguti, Ann. 

 32, 15; Ann. China. [2] 70, 338; [3] 

 16, 5 ; 19; Lieben, Ann. Ill, 121; 

 123, 130; 133, 287; 141, 236; 146, 

 180; 150, 87). By the interaction of 

 dichlorether and zinc ethyl ethylchlpr- 

 ether = 2-ethyl-i-chlorbutyl ether is 

 obtained, and this on heating with 

 hydriodic acid at 140 gives 2-iodo- 

 butane (Lieben, Ann. 150, 96). Subse- 

 quent steps as above under A. 



Or from ethyl alcohol through ethylene 

 glycol [45]. The latter can be con- 

 verted into the iodhydrin = iodethyl 

 alcohol (Simpson, Proc. Roy. Soc. 1O, 

 119; Butleroff and Ossokin, Ann. 144, 

 42 ; 145, 257), which by the action of 

 zinc ethyl gives 2-butanol (B. and O. 

 Ann. 145, 263). Subsequent steps as 

 below under G. 



NOTE : Generators of ethylene thus become, 

 with carbon disulphide, generators of secondary 

 butyl isothiocyanate. 



[G.] From methyl and ethyl alcohols 

 [13 ; 14], formic acid [Vol. II], and 

 carbon disulphide [160]. A mixture of 

 methyl and ethyl iodides with formic 

 ethyl ester is treated with zinc, and 

 the product decomposed by water so as 

 to give 2-butanol = secondary butyl 

 alcohol (Saytzeff, Ann. 175, 374). The 

 alcohol can be converted into the corre- 

 sponding iodide ( = 2-iodobutane) by the 



usual methods, and the latter into the 

 amine and isothiocyanate as before. 



[H.] From erythritol [50] and carlon 

 disulphide [16 0]. Erythritol on heat- 

 ing with hydriodic acid gives 2-iodo- 

 butane (De Luynes, Bull. Soc. [2] 2, 3 ; 

 Ann. 125, 252). Subsequent steps as 

 above under A. 



[I.] Thiocyanic acid [174] can be 

 converted into secondary butyl thio- 

 cyanate by interaction of the potassium 

 salt and secondary butyl iodide (see 

 above under G). The alkyl thiocyanate 

 is probably convertible into the isothio- 

 cyanate by the action of heat (general 

 method : see Hofmann, Ber. 13, 13.50). 



[J.] Isovaleric acid [Vol. II] gives 

 a small quantity of pseudobutylene 

 among the products of the dry distilla- 

 tion of the calcium salt (Dilthey, Ber. 



34, 2119). Subsequent steps as above 

 under B, &c. 



[K.] From acetoacetic acid (ester] 

 [Vol. II] and methyl alcohol [13] 

 through methylethyl ketone (see under 

 methylacetyl carbinol [44 ; B]). The 

 ketone gives secondary butyl alcohol 

 on reduction (Norris and Green, Am. 

 Ch. Journ. 26, 293 : for electrolytic 

 reduction see Elbs and Brand, Zeit. 

 Elektroch. 8, 783). The alcohol with 

 carbon disulphide gives the mustard oil 

 as above under G. 



NOTE : The generators of methylethyl ke- 

 tone referred to under methylacetyl carbinol 

 [44, p. 95] thus become, with carbon disulphide, 

 generators of secondary butyl mustard oil : 



acetic and propionic acids ; acetic and butyric acids ; 

 sine methyl and propionyl chloride ; sine ethyl and 

 acetyl chloride ; ethyl iodide and acetic anhydride, &c. 



[L.] From isoamyl alcohol [22] and 

 carbon disulphide [160]. The alcohol 

 gives pseudobutylene among the pro- 

 ducts of pyrogenic contact decomposi- 

 tion by passing the vapour through 

 a hot iron tube (Wurtz, Ann. 104, 249 ; 

 Butleroff, Ann. 145, 277 ; Ipatieff, Ber. 



35, 1053). From pseudobutylene as 

 above under B. 



[M.] From n-propyl alcohol [15] 

 through n-hexane (see under n-hexyl 

 alcohol [23 ; A]) and carbon disulphide. 

 Hexane gives, among other products, 

 n- and pseudobutylenes when mixed 

 with air and passed over heated platinum 

 (v. Stepski, Monats. 23, 773). 



