6-Bromo-2,2,4,4-tetrafluoro-1,3-benzodioxane → 2,2,4,4-tetrafluoro-4H-benzo[1,3]dioxine-6-carboxylic acid methyl ester
Reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([F:12])([F:11])[O:8][C:7]([F:14])([F:13])[C:6]=2[CH:15]=1>CO.CC#N.CCN(CC)CC.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:7][O:8][C:9]([C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([F:12])([F:11])[O:8][C:7]([F:14])([F:13])[C:6]=2[CH:15]=1)=[O:10]Participants
6
Reactant 1
Product 1
Reagents, catalysts & solvents 4
Conditions
- Temperature
- 75 °C
Procedure
A suspension of 6-bromo-2,2,4,4-tetrafluoro-4H-benzo[1,3]dioxine (4.75 g, 16.6 mmol) and Pd(PPh3)4 (950 mg, 8.23 mmol) in MeOH (20 mL), MeCN (30 mL) and Et3N (10 mL) was stirred under carbon monoxide atmosphere (55 psi) at 75° C. (oil bath temperature) overnight. The cooled reaction mixture was filtered and the filtrate was concentrated. The residue was purified by silica gel column (Petroleum Ether) to give 2,2,4,4-tetrafluoro-4H-benzo[1,3]dioxine-6-carboxylic acid methyl ester (3.75 g, 85%). 1H NMR (CDCl3, 300 MHz) δ 8.34 (s, 1H), 8.26 (dd, J=2.1, 8.7 Hz, 1H), 7.22 (d, J=8.7 Hz, 1H), 3.96 (s, 3H).
Workup
- customThe cooled reaction mixture
- filtrationwas filtered
- concentrationthe filtrate was concentrated
- customThe residue was purified by silica gel column (Petroleum Ether)
Sources & evidence
- ORD record
- ord-e8c2c8636f514e61b01499447d8c5ee0
- Source dataset
- uspto-grants-2010_06
- Patent number
- US07741321B2
Reaction notes
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