tert-Butyl 4-(prop-2-yn-1-yl)piperazine-1-carboxylate → Tert-butyl 4-[3-(6-methoxy-3-oxo-2,3-dihydrobenzofuran-7-yl)prop-2-ynyl]piperazine-1-carboxylate

HRID 1749942Notes

Reaction equation

[CH2:1]([N:4]1[CH2:9][CH2:8][N:7]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:6][CH2:5]1)[C:2]#[CH:3].I[C:18]1[C:26]2[O:25][CH2:24][C:23](=[O:27])[C:22]=2[CH:21]=[CH:20][C:19]=1[O:28][CH3:29]>C(N(CC)CC)C.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.[Cu]I>[CH3:29][O:28][C:19]1[CH:20]=[CH:21][C:22]2[C:23](=[O:27])[CH2:24][O:25][C:26]=2[C:18]=1[C:3]#[C:2][CH2:1][N:4]1[CH2:9][CH2:8][N:7]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:6][CH2:5]1

Participants

Conditions

Temperature: 50 °C

Procedure

A solution of tert-butyl 4-(prop-2-ynyl)piperazine-1-carboxylate (0.449 g, 2.00 mmol) in triethylamine (12 mL) was added with 7-iodo-6-methoxybenzofuran-3(2H)-one (0.580 g, 2.00 mmol), dichlorobis(triphenylphosphine)palladium(II) (0.141 g, 0.200 mmol) and copper(I) iodide (0.0381 g, 0.200 mmol), and the mixture was stirred at 50° C. for 4 hours. The reaction mixture was concentrated, then the solid was suspended in a mixed solvent of 50% ethyl acetate in hexane, and the suspension was filtered. The filtrate was concentrated, and the resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate) to obtain tert-butyl 4-[3-(6-methoxy-3-oxo-2,3-dihydrobenzofuran-7-yl)prop-2-ynyl]piperazine-1-carboxylate (0.473 g, 61%).

Workup

concentrationThe reaction mixture was concentrated
filtrationthe suspension was filtered
concentrationThe filtrate was concentrated
customthe resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate)

Sources & evidence

ORD record: ord-040f737b78704274988c5b93839761b9
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09156827B2

Reaction notes

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