Dimethylformamide → 4-Methoxy-8-methyl-1-naphthaldehyde

To a well stirred solution of 1-methoxy-5-methylnaphthalene (above Step-3 intermediate) (7.0 g, 40.7 mmol) in toluene (8 mL) and DMF (4.7 mL, 61 mmol) at 0° C. was added, POCl3 (4.6 mL, 49.6 mmol) drop wise and the reaction mixture was stirred for 45 min at 0° C. and then refluxed for 2 h. The dark red solution was cooled to RT and poured into a mixture of ice (50 mL) and 10% aq. NaOH (100 mL) with stirring. The crude product was extracted with EtOAc (4×75 mL) and the combined organic layer was washed with 1 N HCl (3×50 mL), water (3×50 mL), brine, dried (Na2SO4) and filtered. The solvent was evaporated and the residue was washed with hexanes (2×15 mL) to afford the desired compound (6.4 g, 79%) as reddish brown solid.

1. temperaturerefluxed for 2 h
2. extractionThe crude product was extracted with EtOAc (4×75 mL)
3. washthe combined organic layer was washed with 1 N HCl (3×50 mL), water (3×50 mL), brine
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. customThe solvent was evaporated
7. washthe residue was washed with hexanes (2×15 mL)

ORD-Eintrag

ord-669c7abb6f67404795d869c33ccbaed5

Quelldatensatz

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09006442B2