Br[C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8]C)=[O:7])=[C:4]([CH3:12])[CH:3]=1.[C:13]([CH:15]1[CH2:17][CH2:16]1)#[CH:14]>C(N(CC)CC)C.[Cu](I)I.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH:15]1([C:13]#[C:14][C:2]2[CH:11]=[CH:10][C:5]([C:6]([OH:8])=[O:7])=[C:4]([CH3:12])[CH:3]=2)[CH2:17][CH2:16]1
Methyl 4-Bromo-2-methylbenzoate (1.0 g, 4.4 mmol) was dissolved in triethylamine (5 mL). To the mixture was added copper iodide (43 mg, 5 mol %), followed by PdCl2(PPh3)2 (157 mg, 5 mol %) and ethynylcyclopropane (1.43 ml, 12 mmol). The mixture was heated in a sealed pressure tube at 80° C. for 3 hours. After completion of the reaction, the triethylamine was evaporated and the residue was dissolved in EtOAc and filtered through Celite®. The organic layer was washed with water, brine, and dried (Na2SO4), then filtered and concentrated under vacuum. The residue was purified by column chromatography on sililca gel using EtOAc-hexane (0-100% gradient) as eluent to give the desired product (630 mg). The product was dissolved in 10 mL of MeOH and 10 mL of 2N LiOH and the mixture was refluxed overnight. The MeOH was evaporated and the basic layer was washed with EtOAC, acidified, and re-extracted with EtOAC. The organic layer was washed with brine, dried (Na2SO4), filtered and concentrated under vacuum to give the desired product as a beige solid (461 mg). m/z 201 (M+1).
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