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

HRID 881098Notes

Reaction equation

HRID 881098 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

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, 1 H), 8.26 (dd, J=2.1, 8.7 Hz, 1 H), 7.22 (d, J=8.7 Hz, 1 H), 3.96 (s, 3 H).

Workup

  1. customThe cooled reaction mixture
  2. filtrationwas filtered
  3. concentrationthe filtrate was concentrated
  4. customThe residue was purified by silica gel column (Petroleum Ether)

Sources & evidence

ORD record
ord-be692fb1e27b48bb98657957f799c4f9
Source dataset
uspto-grants-2015_03
Patent number
US08993600B2

Reaction notes

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