4-(Methoxycarbonyl)-3-methylbenzoic acid → Methyl 4-(hydroxymethyl)-2-methylbenzoate

Participants

Reaction Steps

410 mg of dimethyl 2-methylterephthalate was hydrolyzed via Procedure M and purified by ISCO Combi-Flash to afford 4-(methoxycarbonyl)-3-methylbenzoic acid. 255 mg of 4-(methoxycarbonyl)-3-methylbenzoic acid was cooled to 0° C. in 2 mL of THF before a solution of 2.6 mL of 1M BH3-THF complex in THF was added dropwise. The ice bath was subsequently removed and the reaction was stirred at room temperature until reaction stalled out at ˜50% complete by TLC. The reaction was re-cooled to 0° C. and another 2.6 mL of BH3-THF was added dropwise before the ice bath was removed. Upon completion, the reaction was re-cooled to 0° C. and quenched with 3N HCl dropwise. The aqueous layer was extracted 2 times with Ethyl Acetate and the organic layer was then extracted once with bicarbonate solution and brine, dried over Magnesium Sulfate, filtered and concentrated to give methyl 4-(hydroxymethyl)-2-methylbenzoate. 220 mg of methyl 4-(hydroxymethyl)-2-methylbenzoate was cooled to 0° C. in 5 mL of DCM before adding 260 mg of Triphenylphosphine and 395 mg of NBS. The reaction was concentrated and directly purified via ISCO Combi-Flash to give pure methyl 4-(bromomethyl)-2-methylbenzoate. 255 mg of methyl 4-(bromomethyl)-2-methylbenzoate was reacted via Procedure O to give methyl 2-methyl-4-(methylsulfonylmethyl)benzoate. 250 mg of methyl 2-methyl-4-(methylsulfonylmethyl)benzoate was then hydrolyzed upon heating to 45° C. for 1 hour via Procedure M to give 2-methyl-4-(methylsulfonylmethyl)benzoic acid. 202 mg of 4-chloro-3-(pyridin-2-yl)aniline was coupled to 2-methyl-4-(methylsulfonylmethyl)benzoic acid via Procedure G. The crude product was purified by reverse phase HPLC to yield N-(4-chloro-3-(pyridin-2-yl)phenyl)-2-methyl-4-(methylsulfonylmethyl)benzamide. MS (Q1) 415 (M)+.

Provenance & Evidence