N,N-Diethylaniline → Methyl 8-fluoro-2H-1-benzopyran-5-carboxylate

HRID 1531431Notes

Reaction equation

HRID 1531431 reaction equation
[F:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[O:12][CH2:13][C:14]#[CH:15].C(N(CC)C1C=CC=CC=1)C>C(OCC)C>[F:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[C:4]2[C:3]=1[O:12][CH2:13][CH:14]=[CH:15]2

Participants

4

Reactant 2

HCID 7061N,N-DiethylanilineHCID 11138296Methyl 4-fluoro-3-(prop-2-yn-1-yloxy)benzoate

Product 1

HCID 12016893Methyl 8-fluoro-2H-1-benzopyran-5-carboxylate

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
220 °C

Procedure

Methyl 4-fluoro-3-propargyloxybenzoate (14.0 g, 67.2 mmol) was mixed with N,N-diethylaniline and the reaction was heated to 220° C. for 5 hours. The black reaction mixture was allowed to cool, dissolved in diethyl ether (600 mL) and washed with 2 M HCl in portions (1 L). The aqueous washings were re-extracted with diethyl ether, the combined ether phases were washed with H2O until neutral, treated with brine, dried with MgSO4, filtered, and the solvent was removed in vacuo to give a dark brown crude residue. The crude solid was chromatographed on silica (eluent: methylene chloride/carbon tetrachloride 1:1) to give 11.9 g (85% yield) of a tannish yellow solid as the title compound (mp 73.5-74.5° C.). EIMS (70 eV) m/z (relative intensity) 208 (65, M+), 207 (42), 194 (12), 193 (100), 177 (32), 149 (10), 148 (12).

Workup

  1. customThe black reaction mixture
  2. temperatureto cool
  3. washwashed with 2 M HCl in portions (1 L)
  4. extractionThe aqueous washings were re-extracted with diethyl ether
  5. washthe combined ether phases were washed with H2O until neutral,
  6. additiontreated with brine
  7. dry with materialdried with MgSO4
  8. filtrationfiltered
  9. customthe solvent was removed in vacuo
  10. customto give a dark brown crude residue
  11. customThe crude solid was chromatographed on silica (eluent: methylene chloride/carbon tetrachloride 1:1)

Sources & evidence

ORD record
ord-8f82ab5935d5453da652a1bfbadde460
Source dataset
uspto-grants-2001_03
Patent number
US06197978B1

Reaction notes

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