Reaction #155426

Reaction equation

3-fluoro-4-hydroxybenzaldehyde

pyridine

dimethylcarbamic chloride

→

2-fluoro-4-formylphenyl dimethylcarbamate

Yield 96.1%

Solvents

CH2Cl2

Water

CH2Cl2

Conditions

Workup

1. 1
   OtherTo a 250 mL dry round bottom flask
2. 2
   workup.STIRRINGThe mixture was stirred at room temperature for 62 hours
3. 3
   OtherThe CH2Cl2 layer was separated
4. 4
   Extractionthe aqueous layer was extracted continually with CH2Cl2 (50 mL×3)
5. 5
   DryingThe combined CH2Cl2 solution was dried over Na2SO4
6. 6
   OtherAfter removal of the solvent
7. 7
   Otherthe residue was purified with a silica gel chromatography (heptane/ethyl acetate, gradient eluting)

Procedure

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.

Source