( 276 ) 



oil being wanned is converted into nionacylsnlphonic aeid, wliicli in 

 contact with water yields snlplioiiic acid and carboxylic acid: 



Cn Hon+i CO.O.SOi.O.CO.Cn Mon+i passing into Cn Ho^+i CO.O. 

 SOo.Cn ?Ion CO.OH and then hy H,() into Cn Ho„+i CO.OH and H().S(^2. 



CnHon-CO.OH. 



Specially undertaken experiments led him to this conclusion and 

 also taught him that ^\ hen the acid chloride was used instead of the 

 acid anhydride also two mols. of the latter are required to one mol. 

 of sulphuric acid. The action of chlorosulphonic acid on carboxylic 

 acids, which is also given as a method of preparing sulphonic acids, 

 is understood l»y him to first yield the acid chloride and sul|)huric acid, 

 which then react on each other with formation of the sulphonic acid. 



vSulpho-isobutyric acid itself is a very hygroscopic substance con- 

 taining two mols. of water of crystallisation. The barium salt contains 

 three mols. of water, the sodium salt half a mol. The neutral silver 

 salt is aniiydrous like the acid salt, which latter can only be ol)taine(l 

 in the presence of a large excess of the acid. 



When acting on the sodium salt Avith phosphorus pentachloride 



Dr. Molt, van Charante obtained, according to circumstances, either the 



dichloride or a chloro-anhydride, which is the chloride of the carboxylic- 



and the anhydride of the sulphonic acid function.. The dichloride 



is a colourless liquid, which distils at about 55° under a pressure of 



20 

 1 — Vs Ji'-iii- mercury, with a sp. gr. d — = 1.4696 and a refractive 



power njj = 1.4887; it solidities at — 10°. The sulpho-anliydride- 



carboxy-chloride is solid, crystallises from ligroin and melts at 61°. 



With a little water the dichloride yields suli)lio-chloride-isobutyric 



acid, which is crystalline and melts at 134°. With more \vater, sul- 



pho-isobutyric acid is formed. With methyl alcohol the ester of the 



carboxylic function is generated whilst the sulpho-chloride function 



remains. This ester sulpho-chloride is a liquid, Avliich passed over at 



a pressure of Vi., m.ni. at about 60° and soliditied at 21°. 5 ; the 



20 

 sp. gr. Avas (I — =: 1.3436, the refractive power y//) = 1.46658. 



Treatment with sodium methoxide dissolved in methyl alcohol yielded 



not the dimethyl ester but the ester sodium salt of the suli>lionic acid. 



The dimethyl ester prepared from the neutral silver salt an ith methyl 



iodide \vas a liquid which passed over at a pressure of 1 — V2 m.m. 



between 82° — 78°, soliditied on cooling and then melted at 4°; the 



20 

 sp. gr. Avas (I — =: 1.2584, the index of refraction ///> = 1 .4448 J . 

 4 



