621-36-3

34956-29-1

General procedure for the synthesis of 3-formylphenylacetic acid from 3-methylphenylacetic acid: N-bromosuccinimide (2.37 g, 13.32 mmol) was added to a chloroform (30 mL) solution of 2-(m-tolyl)acetic acid. The reaction mixture was heated to reflux for 8 hours, followed by removal of the solvent under vacuum. The residue was dissolved in a solvent mixture of ethanol (30 mL) and water (30 mL) and hexamethylenetetramine (5 g, 35.7 mmol) was added. The mixture was heated to reflux and maintained for 4 hours. Under reflux conditions, concentrated hydrochloric acid (5.9 mL) was slowly added. Continue heating to reflux for 30 minutes, then cool to room temperature. Water (30 mL) and dichloromethane (30 mL) were added and the organic phase was separated and filtered through hydrophobic glassine. The solvent was removed under vacuum. The residue was dissolved in saturated aqueous sodium bicarbonate and washed with dichloromethane (2 x 15 mL). The aqueous phase was acidified with aqueous 2M hydrochloric acid to pH < 2. The acidified aqueous phase was extracted with dichloromethane (2 x 15 mL), the organic phases were combined and filtered through a hydrophobic glass. The solvent was removed in vacuo to afford 3-formylphenylacetic acid as an off-white solid (1.35 g, 62% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 10.01 (s, 1H), 7.84-7.79 (m, 2H), 7.60-7.48 (m, 2H), 3.75 (s, 2H).LCMS (Method 1): [MH+] = 165, retention time 2.77 min.