Carbon Dioxide → HCID 19782980, compound

Participants

Reaction Conditions

Reaction Steps

The beaker containing the dried phenolate salt and a magnetic stirrer was placed in a 473-mL stainless steel Parr reaction bomb model 452HC2. The bomb was charged with carbon dioxide to a pressure of 830 psi, sealed and then heated in a silicone oil bath over a stirrer-hot plate for 8 hr at 180° C. The pressure increased to 1400 psi during the reaction. After cooling to room temperature, excess CO2 was released, the solid was suspended in 100 mL water and then the mixture was acidified to pH 1 by addition of 5M hydrochloric acid. The mixture was alternately sonicated and stirred vigorously to allow protonation of the insoluble sodium 5-tritylsalicylate. The product was collected on a sintered glass funnel, washed with cold water and dried in vacuum. The solid was suspended in 200 mL 5% aqueous NaHCO3 with sonication and stirring to convert the insoluble 5-tritylsalicylic acid to the insoluble sodium 5-tritylsalicylate while keeping the contaminating 4-tritylphenol unconverted. The solid was collected on a sintered glass funnel, washed with water and dried in vacuum. The product was suspended in 150 mL toluene with stirring and sonication to extract the contaminating phenol. The product was collected on a sintered glass funnel and dried in vacuum. The product was acidified to the salicylic acid by suspending the solid with vigorous stirring and sonication in 150 mL 0.5M hydrochloric acid. TLC of the vacuum-dried product still showed presence of 4-tritylphenol, thus the bicarbonate, toluene, and hydrochloric acid treatment was repeated. The dried product was recrystallized from toluene-acetone to produce 2.1 g (37% yield) of pure 5-tritylsalicylic acid (needles). Mp 234°-237° C. NMR in CDCl3 δ6.80 (d, 1H), δ6.90 (s, 1H), δ7.3 (s, 15H), δ7.8 (d, 1H). IR KBr disk: 2800-3600, 2600 (sh), 1660, 1610, 1490, 1440, 1300, 1200, 750, 700 cm-1.

Provenance & Evidence