Phosphorus oxychloride → 6-Methoxy-1-methyl-3,4-dihydro-2-naphthaldehyde
Reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9]([CH3:13])=[CH:8][CH2:7][CH2:6]2.P(Cl)(Cl)(Cl)=O.[C:19]([O-])(=[O:21])C.[Na+]>>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9]([CH3:13])=[C:8]([CH:19]=[O:21])[CH2:7][CH2:6]2Participants
Conditions
- Temperature
- 72.5 °C
Procedure
To a solution of Compound B (0.44 g, 2.5 mmole) in dry dimethylfomamide (1.3 ml, 16.8 mmole) at ice cooling and stirring under argon atmosphere, phosphorus oxychloride (0.62 ml, 6.65 mmole) was added drop-by-drop in 2 minutes. The reaction mixture was stirred in an oil bath of 70-75° C. for 3 hours. After cooling in an ice bath, ice (6 g) was added, then sodium acetate (anhydrous, 3.7 g) was added, and the mixture (pH 6) was warmed in an oil bath at 70-75° C. for 15 minutes. After cooling, it was extracted with ether (1×10 ml and 3×5 ml), the combined organic solutions were washed with water (3×3 ml), dried (magnesium sulfate), decolorized (with activated carbon), and evaporated. The residue (0.33 g) was recrystallized from cyclohexane (2 ml) and dried over potassium hydroxide in a vacuum giving the pure product 6-Methoxy-1-methyl-3,4-dihydro-2-naphthaldehyde (Compound C, 0.22 g, 44%) as light brown crystals, mp. 70-72° C.
Workup
- temperatureAfter cooling in an ice bath
- temperatureAfter cooling
- extractionit was extracted with ether (1×10 ml and 3×5 ml)
- washthe combined organic solutions were washed with water (3×3 ml)
- dry with materialdried (magnesium sulfate)
- customevaporated
- customThe residue (0.33 g) was recrystallized from cyclohexane (2 ml)
- dry with materialdried over potassium hydroxide in a vacuum
Sources & evidence
- ORD record
- ord-e27d3c73318d4401975197eb1a2b4c77
- Source dataset
- uspto-grants-2012_01
- Patent number
- US08093269B2
Reaction notes
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