78 Journal of the Mitchell Society [January 



color. If it is recrystallized from water, it becomes brilliant 

 red. It is not a case of isomerism, for it loses one molecule of 

 water at 100° and regains its yellow color. 



EXPERIMENTAL PART 



3-Metlioxy-Jf-Jiydroxyhenzal-p-arinnohenzoic Acid, CII3O.- 

 OH.CeHgCH : NC6H4CO0H, is prepared by boiling 1.37 grams 

 (one mol) p-aminobenzoic acid and 1.52 grams (one mol) va- 

 nillin in 100 cc. toluene with the addition, of 5 cc. alcohol. A 

 little alcohol greatly diminishes the amount of toluene required. 

 After boiling five hours under a reflux condenser, the solution is 

 allowed to cool, the condensation product crystallizing out 

 abundantly. A second crop of crystals from the mother liquor 

 increased the yield to a total of 2.6 grams or 96% of the theo- 

 retical. The crude product, which melts at 204^6° was recrys- 

 tallized from 200 cc. of toluene. The pure substance is deep 

 yellow, consists of thin plates and melts at 211 — 2°. 



Calculated for CisHwO^N : C, 66.42 ; H, 4.80 ; N, 5.15 

 Found : C, 66.44 ; H, 5.12 ; N, 5.69 



It was noticed that the rich, yellow crystals were often, mixed 

 with red ones. The first thought Avas that an isomeric com- 

 pound was present, since some cases among analogous com- 

 pounds are known, as the o-hydroxybenzalanthranilic acid 

 described by Wolf. The whole mass turned red however in 

 water and upon recrystallizing from boiling water a brilliant 

 red substance, m. 104 — 6°, was obtained. After complete drying 

 in the air, the product was heated to constant weight at 100°. 



1.7860 g. lost at 100° 0.1150 g. HoO. 



Calculated for CsHisOiN.H.O : H.O, 6.22; found: H2O, 6.44- 



3-Methoxy-Jr1iyd}VxyhenzaIethyl-p-ami)iohenzoate, CHoO.- 

 OH.CeHgCH :^"G^H,00oCoH5, is prepared by boiling 1 gram- 

 molecule of ethyl-p-aminobenzoate with 1 gram-molecule vanil- 

 lin in 10 cc. benzene for six hours under a reflux condenser. 

 The solvent was then evaporated oif and the residue recrystal- 

 lized three times from alcohol. The crystals, which are thin 

 yellow i^lates, melt at 145° (cor.). 



