Phosphoric Acid → 2,2-Dimethyl-5-(3-methyl-3-buten-1-ynyl)-4H-(1,3)benzodioxin-4-one

HRID 1955991Notes

Reaction equation

HRID 1955991 reaction equation
[CH3:1][C:2](=[CH2:5])[C:3]#[CH:4].C(N(CC)CC)C.[CH3:13][C:14]1([CH3:33])[O:19][C:18]2[CH:20]=[CH:21][CH:22]=[C:23](OS(C(F)(F)F)(=O)=O)[C:17]=2[C:16](=[O:32])[O:15]1.P(=O)(O)(O)O>CN(C)C=O.O>[CH3:13][C:14]1([CH3:33])[O:19][C:18]2[CH:20]=[CH:21][CH:22]=[C:23]([C:4]#[C:3][C:2]([CH3:5])=[CH2:1])[C:17]=2[C:16](=[O:32])[O:15]1

Participants

7

Reactant 4

HCID 1004Phosphoric AcidHCID 8471TriethylamineHCID 62323Isopropenylacetylene2×HCID 108927482,2-Dimethyl-4-oxo-4H-benzo[D][1,3]dioxin-5-YL trifluoromethanesulfonate

Product 1

HCID 152794382,2-Dimethyl-5-(3-methyl-3-buten-1-ynyl)-4H-(1,3)benzodioxin-4-oneYield 62.8%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
115 °C

Procedure

0.64 g (0.92 mmol) of bistriphenylphosphinepalladium dichloride, 4.4 ml (46 mmol) of 3-methyl-3-buten-1-yne and 24 ml of triethylamine are added under nitrogen to a solution of 15.0 g (46 mmol) of 2,2-dimethyl-5-trifluoromethylsulfonyloxy-4H-(1,3)benzodioxin-4-one in 150 ml of dimethylformamide. The mixture is heated at 115° C. for 0.5 h, a further 6.6 ml of 3-methyl-3-buten-1-yne are then added at this temperature in the course of 1 h and the reaction solution is subsequently stirred for 15 min. After cooling, it is poured into 500 ml of water containing phosphoric acid (pH 3) at 0° C. and extracted with methyl tert-butyl ether, and the combined organic phases are carefully washed with water and saturated sodium chloride solution, dried over sodium sulfate and concentrated. 14 g of a dark oil remain, which is chromatographed on silica gel using n-hexane/ethyl acetate. 7.0 g of colorless crystals are obtained, m.p. 60 ° C. (cf. Table 1, No. 1.009).

Workup

  1. temperatureAfter cooling
  2. extractionextracted with methyl tert-butyl ether
  3. washthe combined organic phases are carefully washed with water and saturated sodium chloride solution
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated
  6. customwhich is chromatographed on silica gel

Sources & evidence

ORD record
ord-7b8ad6a6e719429e9b0b611e1cc512dd
Source dataset
uspto-grants-1998_07
Patent number
US05777118

Reaction notes

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