Water → 4,5-difluoro-2-methyl-7-propyl-7H-furo[3,2-f]chromene

HRID 2244849Notes

Reaction equation

HRID 2244849 reaction equation
[F:1][C:2]1[C:3]([F:15])=[C:4]2[O:8][C:7]([CH3:9])=[CH:6][C:5]2=[C:10]([CH:13]=O)[C:11]=1[OH:12].[CH:16](B(O)O)=[CH:17][CH2:18][CH2:19][CH3:20].C(NCC1C=CC=CC=1)C1C=CC=CC=1.O>O1CCOCC1>[F:15][C:3]1[C:2]([F:1])=[C:11]2[C:10]([CH:13]=[CH:16][CH:17]([CH2:18][CH2:19][CH3:20])[O:12]2)=[C:5]2[CH:6]=[C:7]([CH3:9])[O:8][C:4]=12

Participants

6

Reactant 4

HCID 962WaterHCID 7656DibenzylamineHCID 27346091-Pentenylboronic acidHCID 592152776,7-Difluoro-5-hydroxy-2-methylbenzofuran-4-carbaldehyde

Product 1

HCID 592152794,5-difluoro-2-methyl-7-propyl-7H-furo[3,2-f]chromene

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

4.0 g (18.9 mmol) of 6,7-difluoro-5-hydroxy-2-methylbenzofuran-4-carbaldehyde are stirred for 20 h at 90° C. together with 2.79 g (24.5 mmol) of 1-penteneboronic acid and 0.72 ml (3.73 mmol) of dibenzylamine in 95 ml of 1,4-dioxane. Water is added to the reaction mixture, which is then extracted with MTBE. The organic phase is separated off, and the aqueous phase is extracted with MTBE. The combined organic phases are washed with water and sat. sodium chloride soln. The solution is dried using sodium sulfate and concentrated to dryness. The crude product is firstly purified by column chromatography (SiO2, 1-chlorobutane) and subsequently crystallised from methanol, giving 4,5-difluoro-2-methyl-7-propyl-7H-furo[3,2-f]chromene as a yellow, crystalline solid.

Workup

  1. extractionis then extracted with MTBE
  2. customThe organic phase is separated off
  3. extractionthe aqueous phase is extracted with MTBE
  4. washThe combined organic phases are washed with water and sat. sodium chloride soln
  5. customThe solution is dried
  6. concentrationconcentrated to dryness
  7. customThe crude product is firstly purified by column chromatography (SiO2, 1-chlorobutane)
  8. customsubsequently crystallised from methanol

Sources & evidence

ORD record
ord-fbdfb01c41624ffd8106d84fa73c6e4f
Source dataset
uspto-grants-2010_03
Patent number
US07678929B2

Reaction notes

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