Pyridine → 2-Fluoro-4-formylphenyl dimethylcarbamate

To a 250 mL dry round bottom flask were added 3-fluoro-4-hydroxybenzaldehyde (4.90 g, 35.0 mmol), anhydrous CH2Cl2 (20 mL) and pyridine (3.68 mL, 45.5 mmol). The mixture was stirred in an ice-water bath, then dimethylcarbamic chloride (3.54 mL, 38.5 mmol) was added. The mixture was stirred at room temperature for 62 hours. Water (80 mL) and CH2Cl2 (50 mL) were added to the reaction mixture. The CH2Cl2 layer was separated, and the aqueous layer was extracted continually with CH2Cl2 (50 mL×3). The combined CH2Cl2 solution was dried over Na2SO4. After removal of the solvent, the residue was purified with a silica gel chromatography (heptane/ethyl acetate, gradient eluting) to give 2-fluoro-4-formylphenyl dimethylcarbamate (7.10 g) as white solid. Yield: 96%. 1H NMR (CDCl3, 300 MHz): δ=9.92 (d, J=1.8 Hz, 1H), 7.69-7.64 (m, 2H), 7.40 (t, J=7.5 Hz, 1H), 3.13 (s, 3H), 3.03 (s, 3H). 13C NMR (CDCl3, 75.5 MHz): δ=190.0, 156.5, 153.0 (d, J=17.1 Hz), 144.2 (d, J=12.8 Hz), 134.7 (d, J=5.5 Hz), 126.6 (d, J=3.6 Hz), 124.8, 116.5, 116.2, 36.8, 36.5. 19F NMR (CDCl3, 282.3 MHz): δ=−127.5.

1. customTo a 250 mL dry round bottom flask
2. stirringThe mixture was stirred at room temperature for 62 hours
3. customThe CH2Cl2 layer was separated
4. extractionthe aqueous layer was extracted continually with CH2Cl2 (50 mL×3)
5. dry with materialThe combined CH2Cl2 solution was dried over Na2SO4
6. customAfter removal of the solvent
7. customthe residue was purified with a silica gel chromatography (heptane/ethyl acetate, gradient eluting)

ORD-Eintrag

ord-d5dbd6df8e6a4eb8a258e0e0b9f906c6

Quelldatensatz

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08822435B2