42 The Philippine Journal of Science 1913 



it is clear that the degree of hydrolysis must be different. The 

 two portions of the curve do not quite join, but the variation is 

 so slight that it is not shown in the chart. 



METHYL ETHER OF SALICYLIC ACID, AND THE METHYL ETHER OF 

 METHYL SALICYLATE. FIG. 3 



The methyl ether of salicylic acid may be obtained easily and 

 with a good yield by the following method. One hundred grams 

 of salicylic acid and 70 grams of sodium hydroxide are dissolved 

 in 300 cubic centimeters of water. This concentration of alkali 

 converts about 97 per cent of the acid into the di-sodium salt. 

 One hundred grams of methyl sulphate are added in small por- 

 tions with constant shaking, keeping the temperature below 40°. 

 When the methyl sulphate has disappeared, the solution is 

 strongly acidified with hydrochloric acid and extracted with 

 ether. The ether layer is separated, washed with water, and the 

 ether removed by evaporation. The residue is heated for one 

 hour on the water bath with an excess of lime water and filtered. 

 The insoluble residue of calcium salicylate is repeatedly extracted 

 with boiling water, and the combined nitrates acidified with 

 hydrochloric acid. The methyl ether of salicylic acid is deposited 

 upon cooling in large monoclinic plates. It should be recrystal- 

 lized from water until ferric chloride shows no trace of salicylic 

 acid. Its methyl ester is easily obtained with methyl alcohol 

 and hydrogen chloride, and boils at 245-246°. This boiling point 

 agrees with that found by Schreiner 15 and not with the lower 

 value given by Folsing. 16 The ester-ether was saponified, and 

 the resulting acid identified as the methyl ether of salicylic acid. 

 The absorption spectra of these two compounds in neutral alcohol 

 solutions are identical. We have photographed them in the 

 presence of 1 and 5 equivalents of sodium ethoxide. Under 

 these conditions the absorption band heading 1/A=3440 in the 

 methyl ether of salicylic acid is shifted toward the shorter wave 

 lengths to 1/A=3640, both concentrations of alkali giving prac- 

 tically identical results. The persistence of this band is, at the 

 same time, reduced, and the incipient band in the benzene region 

 of the spectrum is lost. It is to be noted that, while alkali causes 

 a shift toward the red in the compounds previously discussed, 

 the shift in this instance is in the opposite direction. The former 

 shift is characteristic of enol-keto tautomerism, and is not shown 

 when the labile hydrogen atom is replaced by an alkyl group, 



"Ann. Chem. Pharm. (1879), 197, 1. 



° Ber. d. deutschen chem. Ges. (1884), 17, 486. 



