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IOWA ACADEMY OP SCIENCE 
from 60°, at Which it softened, to 101°, at which the final melt- 
ing occurred. An effort was made to use pyridine and alcohol 
on the ether solution of the acid chloride. It resulted in a good 
yield of the methyl ester sulphone chloride, melting nicely at 
101°, but no> dimethyl ester was formed. 
Failing by the methods above given, recourse was had to 
Kastle’s method of treating the dry silver salt of the methyl 
ester acid with methyl iodide. The silver salt of the methyl 
ester sulphonic acid was made by adding silver nitrate solu- 
tion to the syrup obtained by boiling down a solution of the 
acid chloride in alcohol. It crystallized from the strong solu- 
tion in cottony needles which were sucked dry and used without 
purification. The silver nitrate which was in excess would 
finally precipitate as silver iodide, and not interfere with the 
formation of the diester. 
The salt was dried at 110° (it puffs at 140° unless quite pure) 
and was ground in a mortar.^ It was then placed in a pressure 
bottle and methyl iodide added in excess. Immediately a rapidly 
increasing yellow precipitate of silver iodide came down. The 
mixture was heated, however, at 100° under the pressure of 
its vapor in order to make sure of the completion of the reaction. 
The excess of the methyl iodide was then evaporated and the 
dry residue extracted with absolute ether and filtered. The 
product obtained by evaporating the ether was recrystallized 
from absolute methyl alcohol and it then gave a constant melt- 
ing point of 94.5°. This melting point is remarkably close to 
that of the free 4-nitro-5-methyl-2-sulphobenzoic acid, but the 
substance is insoluble in water, and gives no acid reaction. It 
contains no chlorine, as was shown by hydrolyzing with potas- 
sium hydroxide and testing with silver nitrate. The diester 
was analyzed for nitrogen only, on account of the small amount 
of the material available. 
.1869 grams substance required 6.12 cc .1088N HCl- 
Theory for CioHiiO.NS Pound 
Nitrogen, 4.85 per cent. 4.98 per cent. 
derivatives obtained by the action op phenol on THE 
ACID CHLORIDES. 
The action of phenol upon the acid chlorides offers no new 
facts bearing on the constitution of the latter. The products are 
of the same general nature as those given by the alcohols. Both 
acid chlorides seem to give practically the same derivatives. 
