Dimethylformamide → 4-Chloro-2-[(2-methylene-3-butenyl)oxy]benzaldehyde
Reaction equation
[Cl:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[O:7])=[C:4]([OH:10])[CH:3]=1.CN(C=O)C.Br[CH2:17][C:18]([CH:20]=[CH2:21])=[CH2:19].C(=O)([O-])[O-].[K+].[K+]>C(Cl)Cl.O>[Cl:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[O:7])=[C:4]([O:10][CH2:19][C:18](=[CH2:17])[CH:20]=[CH2:21])[CH:3]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 70 °C
Procedure
To a solution of 4.1 g (0.026 mol) of 4-chloro-2-hydroxybenzaldehyde and 27 mL of DMF was added 5 g (0.034 mol) of 2-bromomethyl-1,3-butadiene and 7.2 g (0.052 mol) of potassium carbonate. The resulting mixture was heated at 70° C. for 4 h and then cooled to room temperature and poured into a mixture of 100 mL of water and 100 mL of methylene chloride. The aqueous layer was extracted with two 100 mL portions of methylene chloride and the combined organic layers were washed twice with 100 mL of water, twice with 100 mL of saturated sodium bicarbonate solution, dried over magnesium sulfate and concentrated to give 4.9 g of an oil. Purification by flash chromatography using 250 g of silica gel and eluting with 10:1 hexanes-EtOAc gave 2.6 g of the desired product. 200 MHz 1H NMR (CDCl3): δ4.82 (s, 2H), 5.18-5.42 (m, 4H), 6.45 (dd, 1H), 7.01 (s, 1H), 7.05 (d, 1H), 7.79 (d, 1H), 10.48 (s, 1H).
Workup
- temperaturecooled to room temperature
- extractionThe aqueous layer was extracted with two 100 mL portions of methylene chloride
- washthe combined organic layers were washed twice with 100 mL of water, twice with 100 mL of saturated sodium bicarbonate solution
- dry with materialdried over magnesium sulfate
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-f54ce4d81fe24c02a716a1fe9c707d60
- Source dataset
- uspto-grants-1995_12
- Patent number
- US05474998
Reaction notes
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