[CH3:1][O:2][C:3]1[C:12]2[C:7](=[C:8]([CH3:13])[CH:9]=[CH:10][CH:11]=2)[CH:6]=[CH:5][CH:4]=1.CN([CH:17]=[O:18])C.O=P(Cl)(Cl)Cl.[OH-].[Na+]>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]1[C:12]2[C:7](=[C:8]([CH3:13])[CH:9]=[CH:10][CH:11]=2)[C:6]([CH:17]=[O:18])=[CH:5][CH:4]=1To 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.
読み込み中…
