Water → 7-(2-cyclopropylethynyl)-3,4-dihydro-2H-1-benzopyran-4-one

HRID 63087Notes

Reaction equation

HRID 63087 reaction equation
Br[C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1.C(N(CC)CC)C.[CH:20]1([C:23]#[CH:24])[CH2:22][CH2:21]1.O>CN(C=O)C.[Cu]I>[CH:20]1([C:23]#[C:24][C:2]2[CH:3]=[CH:4][C:5]3[C:6](=[O:12])[CH2:7][CH2:8][O:9][C:10]=3[CH:11]=2)[CH2:22][CH2:21]1

Participants

7

Reactant 4

HCID 962WaterHCID 8471TriethylamineHCID 138823CyclopropylacetyleneHCID 223357367-bromo-3,4-dihydro-2H-1-benzopyran-4-one

Product 1

HCID 867282157-(2-cyclopropylethynyl)-3,4-dihydro-2H-1-benzopyran-4-oneYield 88.3%

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of 7-bromochroman-4-one (2.0 g, 8.8 mmol) in DMF (10 mL) was added CuI (380 mg, 1.7 mmol), Pd(PPh3)Cl2 (540 mg, 0.8 mmol) and triethylamine (5 mL) under nitrogen at rt. The suspension was warmed to 100° C. and then cyclopropylacetylene (1.1 g, 17.6 mmol) was added dropwise. The mixture was stirred at 100° C. under nitrogen for 2 h. The reaction mixture was cooled to rt, poured into water, and extracted with EtOAc. Organics were separated and washed with brine, dried (Na2SO4), and concentrated. The residue was purified by silica gel chromatography to give 1.65 g (88%) of the title compound as a tan solid. 1H NMR (300 MHz, CDCl3): δ 0.83-0.93 (4H, m), 1.44-1.49 (1H, m), 2.79 (2H, t, J=6.6 Hz), 4.52 (2H, t, J=6.6 Hz), 6.96-7.00 (2H, m), 7.79 (1H, d, J=7.8 Hz). [M+H] calc'd for C14H12O, 213; found 213.

Workup

  1. temperatureThe reaction mixture was cooled to rt
  2. extractionextracted with EtOAc
  3. customOrganics were separated
  4. washwashed with brine
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated
  7. customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-92a41fbae0444846a8710469fb61aed5
Source dataset
uspto-grants-2016_09
Patent number
US09447045B2

Reaction notes

Loading…