Dimethylformamide → 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.CN(C)[CH:16]=[O:17].P(Cl)(Cl)(Cl)=O.C([O-])(=O)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:16]=[O:17])[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 dimethylformamide (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-961b812cbe8f4a7b8416553ffa44e2d0
- Source dataset
- uspto-grants-2013_11
- Patent number
- US08592458B2
Reaction notes
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