Hydrochloric Acid → 2,4-Dimethyl-6-methylsulfanyl-benzaldehyde

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Reaction Conditions

Reaction Steps

A solution of 1,3-dimethyl-5-methylsulfanyl-benzene (8.95 g; 0.059 mol) in 120 ml of dry dichloromethane is cooled to −15° C. under nitrogen. Titanium tetrachloride (12.9 ml; 0.117 mol) is added dropwise, and the resulting dark solution is cooled to −78° C. Dichloromethyl methylether (7.4 ml; 0.082 mol) is then added dropwise during 30 min. and the temperature is allowed to rise to 0° C. After stirring for 20 min at 0° C., the reaction mixture is poured onto 80 g of ice and 10 ml of concentrated hydrochloric acid. The organic phase is separated, washed neutral with water, dried over magnesium sulfate and evaporated in vacuo. A yellow solid (10.5 g; 99%) consisting of a regioisomeric mixture of 2,4-dimethyl-6-methylsulfanylbenzaldehyde and 2,6-dimethyl-4-methylsulfanyl-benzaldehyde is obtained, from which the pure 2,4-dimethyl-6-methylsulfanyl-benzaldehyde (6.9 g; 65%), m.p. 64-66° C., is isolated by recrystallization from hexane. 1H-NMR (CDCl3). δ [ppm]: 10.58 (s, 1H), 6.99 (s, 1H), 6.83 (s, 1H), 2.60 (s, 3H), 2.46 (s, 3H), 2.36 (s, 3H).

Provenance & Evidence