Acetone → 3-Chloro-4,5-diethoxybenzoic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of methyl 3-chloro-4,5-dihydroxybenzoate (D68) (1.0 g) in acetone (50 mL) stirred at room temp was added K2CO3 (6.9 g) and bromoethane (5.5 g). The reaction mixture was stirred at 60° C. for 18 h. After filteration, the filtrate was concentrated under reduced pressure. The residue was dissolved in tetrahydrofuran (20 mL) and methanol (20 mL), a solution of NaOH (1.0 g) in water (20 mL) was added to the above solution. The resulted mixture was stirred for 4 h and then the organic solvent was removed in vacuo. The aqueous layer was acidified with concentrated HCl to pH around 1. The solid was filtered and dried in vacuo to afford 3-chloro-4,5-bis(ethyloxy)benzoic acid (D69) (769 mg). δH (DMSO-d6, 400 MHz): 1.29 (3H, t), 1.36 (3H, t), 4.08-4.15 (4H, m), 7.46 (1H, d), 7.53 (1H, d), 13.16 (1H, br s). MS (ES): C11H13ClO4 requires 244; found 245.1 (M+H+).

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