94 GIBBS, WILLIAMS, AND PRATT. 
without at the same time causing decomposition. No evidence 
of decomposition to para quinone has been detected in the cold. 
NOH 
“a 
The oxime |__|] COO.C2H; described by Jeanrenaud® has not 
I 
NOH 
been prepared by us but the mono-oxime C,H, :0,:NOH,.COOCH, 
has been obtained in the following manner: 
The calculated amount of hydroxylamine hydrochloride was added to 
an alcoholic solution of the methyl ester of gentisic acid and, while heating 
on the water bath, small amounts of hydrogen peroxide were added at 
intervals until further additions produced no increased darkening of the 
color. After heating eight hours, the dark red solution was poured into 
water causing the separation of a heavy, brownish red oil. This was washed 
with water until free from hydroxylamine, then with small amounts of ethyl 
ether until practically free from unoxidized ester. This oil is slightly 
soluble in water, more soluble in ether, coloring the latter solvent a clear 
dark red, and solidifies at low temperatures to an amorphous condition. 
Further purification was effected by precipitation with dilute sulphuric 
acid from a solution in dilute alkali, in which the oil is very soluble. 
The brown flocculent product thus obtained was centrifugated, washed with 
cold water to remove inorganic salts, and dried at 100°. It was an amor- 
phous, dark, chocolate-colored, almost black, powder. 
The analysis was effected by the following method which has 
been tested with various oximes and found satisfactory.** The 
=NOH group is first reduced to the hydroxamic acid group by 
boiling with dilute sulphuric acid and zine dust and then the 
nitrogen determined by the Kjeldahl method. 
N - f 
= sulphuric acid. 
19 SUP 
Found Calculated 
(per cent). (per cent). 
Nitrogen in C.H:,:0,:NOH,.COOCH: 7.28 7.73 
0.2231 gram substance required 11.6 cubic centimeters 
Considering the difficulties experienced in purifying the small 
yield, the analysis is satisfactory and further establishes the 
fact that the methyl ester of gentisic acid forms a quinone with- 
out the loss of carbon dioxide. The nitrogen content of an 
oxime of this constitution (C,H,.CH,,:0,:NOH) would be 10.22 
per cent, much greater than that found on analysis. 
* Ber. d. deutschen chem. Ges. (1889), 22, 1283. This compound will be 
further discussed in a later article. 
* Orndorff and Pratt, Am. Chem. Journ. (1912), 47, 94. 
