vm, a, 3 Pratt and Gibbs: Tivo Phthaloximes 179 



handled with alcohol alone as a solvent. A mixture of equal 

 parts of alcohol and acetone proved satisfactory for this region. 

 The yellow isomer shows greater total absorption in the visible 

 spectrum. With decreasing concentration the curves approach 

 until they are practically identical, but separate again as they 



reach the absorption band at r- = 3400 where the white isomer 



shows slightly greater persistence. The benzene bands, numbers 

 1, 2, 4, and 6, are clearly defined in neutral or acid solution al- 

 though not separately plotted in fig. 1. 



The absorption curve of the benzoate of white phthaloxime is 

 also shown in fig. 1. The spectra of the methyl ethers and ace- 

 tates were also studied, but are not plotted as the curves fall be- 

 tween the oximes and the benzoates. All of these curves are very 

 similar. The absorption bands extend to about the same dilution 

 for each compound, but the intervening transmitted portion is 



very different in each case. The transmission band at r- = 3676 



decreases from about 2.5 in the oximes and methyl ethers to 

 2.4 in the acetates and 2.15 in the benzoates. The transmission 

 bands bounding the other benzene absorption bands show about 

 the same decrease; that is, the transmission band heading at 



r- = 3870 persists to about log. 2.32 in the oximes, 2.25 in the 

 acetates, and 2.20 in the benzoates. 



THE METHYL ETHERS OF THE TWO PHTHALOXIMES 



The methyl ethers of the two oximes were made by treating the 

 respective silver salts suspended in ether with methyl iodide. 

 The reaction proceeds rapidly at room temperature with the 

 separation of silver iodide. The ethers were extracted from the 

 residue and recrystallized from alcohol in the form of long 

 needles, that of the white oxime being colorless while the cor- 

 responding derivative of the yellow oxime is faintly yellow. Both 

 ethers melt at 133° uncorrected. 



THE BENZOATES OF THE TWO PHTHALOXIMES 



The two benzoates were similarly made from the silver salt?, 

 and benzoyl chloride. They crystallize from alcohol in columns, 

 one colorless and the other faintly yellow. Both melt at 171°. 5 

 uncorrected. The benzoates may conveniently be prepared also 

 from benzoyl chloride and an alkali salt of the oxime dissolved in 

 water. 



