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

HRID 1847194Notes

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

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

temperatureThe reaction mixture was cooled to rt
extractionextracted with EtOAc
customOrganics were separated
washwashed with brine
dry with materialdried (Na2SO4)
concentrationconcentrated
customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record: ord-829eac38f80d475989c7486437ca3d9a
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08952151B2

Reaction notes

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