Sulfuric Acid → 2-(carboxymethyl)-5-methoxybenzoic acid
Reaction equation
[Cl-].[Cl-].[Ca+2].OS(O)(=O)=O.[CH3:9][O:10][C:11]1[CH:12]=[CH:13][CH:14]=[C:15]([CH:19]=1)[C:16]([OH:18])=[O:17]>>[C:16]([CH2:15][C:14]1[CH:13]=[CH:12][C:11]([O:10][CH3:9])=[CH:19][C:15]=1[C:16]([OH:18])=[O:17])([OH:18])=[O:17]Participants
4
Procedure
A oven-dried 25 mL three neck round-bottomed flask containing a stirring bar was fitted with a drying tube (CaCl2) and charged with concentrated H2SO4 (12.0 mL). Dichlorovinyl)-5-methoxybenzoic acid (1.69 g, 6.83 mmol) was added portion wise to the stirred solution over 20 min. so that each additional portion was added only after the previous one was completely dissolved. After the addition was complete the reaction was left stirring at room temperature for 2 h and then it was poured onto ice. A precipitate formed and the mixture was stirred until the ice was dissolved. The precipitate was filtered, washed with cold water and dried to give 2-(carboxymethyl)-5-methoxybenzoic acid as an off-white solid (1.18 g, 82%). Spectral data for this compound were consistent with those in the literature. M.p. 175-177° C. (lit. m.p. 180-182° C.); 1H NMR (400 MHz, DMSO-d6): δ=12.36 (br. s, 2H), 7.39 (d, J=2.6 Hz, 1H), 7.24 (d, J=8.4 Hz, 1H), 7.08 (dd, J=8.4 Hz, J=2.6 Hz, 1H), 3.84 (s, 2H), 3.78 (s, 3H).