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 2420835Notes

Reaction equation

HRID 2420835 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-70eeeaf8e136460bb6e4e57ae9940066
Source dataset
uspto-grants-2011_06
Patent number
US07956052B2

Reaction notes

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