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 401548Notes

Reaction equation

HRID 401548 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, 1H), 8.26 (dd, J=2.1, 8.7 Hz, 1H), 7.22 (d, J=8.7 Hz, 1H), 3.96 (s, 3H).

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-927c15d7aaf2425bba98150dc6294594
Source dataset
uspto-grants-2014_06
Patent number
US08741933B2

Reaction notes

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