反应详情

A solution of 377 mg of methyl 5-(hydroxymethyl)-2-methylbenzoate and 0.8 mL (9.17 mmol) of oxalyl chloride in 20 mL of CH2Cl2 was cooled to −78° C. To this solution was added 1.1 mL (15.5 mmol) of DMSO dropwise, and after stirring for 10 min., 3.2 mL of Et3N was added and stirring was continued at −78° C. for 10 min. The dry ice-acetone bath was removed, and the mixture was allowed to warm to r.t. and after 2 h, 30 mL of sat. NH4Cl solution was added. The organic layer was washed with 25 mL of brine, dried over Na2SO4, filtered, and concentrated. Purification by flash silica gel chromatography (10% EtOAc/hexanes) provided 268 mg of methyl 5-formyl-2-methylbenzoate as a red liquid in 71% yield with some impurity.

1. stirringstirring
2. waitwas continued at −78° C. for 10 min
3. customThe dry ice-acetone bath was removed
4. addition30 mL of sat. NH4Cl solution was added
5. washThe organic layer was washed with 25 mL of brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated
9. customPurification by flash silica gel chromatography (10% EtOAc/hexanes)