Methanol → HCID 13674974, compound

To a solution of 2,3-dihydro-1,4-benzodioxine-2-carboxylic acid (1.0 g, 5.6 mmol) in methylene chloride (10 mL) and methanol (10 mL) at 0° C. was added trimethylsilyldiazomethane (2 M in hexane) until yellow color persisted, and the reaction was stirred at room temperature for 15 min. The reaction mixture was concentrated to dryness and azeotroped with toluene. The residue was dissolved in anhydrous tetrahydrofuran (20 mL), and was added methyl iodide (1.8 mL, 28 mmol) and potassium hexamethyldisilazide (0.5 M in toluene, 17 mL, 8.5 mmol) at −78° C. The reaction was allowed to warm to room temperature over 4 h, diluted with ethyl acetate (100 mL), washed with saturated ammonium chloride (100 mL) and water (100 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to dryness to give the title compound. 1H NMR (500 MHz, CD3OD): δ 7.07 (ddd, 1H), 6.97 (dd, 1H), 6.94 (dd, 1H), 6.85 (ddd, 1H), 5.52 (d, 1H), 4.64 (d, 1H), 3.86 (s, 3H), 3.83 (s, 3H). LC-MS: m/e 231 (M+Na)+ (2.6 min).

1. concentrationThe reaction mixture was concentrated to dryness
2. customazeotroped with toluene
3. dissolutionThe residue was dissolved in anhydrous tetrahydrofuran (20 mL)
4. temperatureto warm to room temperature over 4 h
5. washwashed with saturated ammonium chloride (100 mL) and water (100 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated to dryness

ORD record

ord-9fee93645f144654b394997a4044b70f

Source dataset

uspto-grants-2008_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07348456B2