Potassium Carbonate → 3-Amino-4-chlorobenzaldehyde

Temperatur

5 °C

4-Chloro-3-nitrobenzaldehyde (4.00 mg, 21.6 mmol) in CH2Cl2 (150 mL) at 23° C. was treated with water (50 mL) and N, N′-diheptyl-4,4′-bipyridinium dibromide (220 mg, 10 mg/mmol of substrate). The biphasic mixture was cooled to 5° C. and treated with a solution of sodium dithionite (15.0 g, 86.0 mmol) and K2CO3 (13.4 g, 87.0 mmol) in water (45 mL). The cooling bath was removed and the biphasic mixture stirred vigorously at 23° C. for 4 hours. The mixture was partitioned between additonal CH2Cl2 (75 mL) and water (50 mL) and the aqueous layer was extracted with CH2Cl2 (75 mL). The organic portions were washed with brine (75 mL) and dried (Na2SO4). The residue was treated with ethyl acetate (25 mL) and silica gel (75 g) and the suspension was filtered through a small pad of Celite, rinsing with 10% ethyl acetate/CH2Cl2 (15 mL). The filtrate was concentrated to provide the title compound as an off-yellow powder (3.44 g, 22%).

1. customThe cooling bath was removed
2. customThe mixture was partitioned between additonal CH2Cl2 (75 mL) and water (50 mL)
3. extractionthe aqueous layer was extracted with CH2Cl2 (75 mL)
4. washThe organic portions were washed with brine (75 mL)
5. dry with materialdried (Na2SO4)
6. additionThe residue was treated with ethyl acetate (25 mL) and silica gel (75 g)
7. filtrationthe suspension was filtered through a small pad of Celite
8. washrinsing with 10% ethyl acetate/CH2Cl2 (15 mL)
9. concentrationThe filtrate was concentrated

ORD-Eintrag

ord-c2a40575cb554cf5aedc4426b7883632

Quelldatensatz

uspto-grants-2003_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06642222B2