N,N-Diethylaniline → Methyl 4-hydroxy-3-(1-vinylcyclopentyl)benzoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The reaction mixture of methyl 4-(2-cyclopentylideneethoxy)benzoate 26.2 (0.50 g, 2.0 mmol), N,N-diethylaniline (3.2 mL, 20 mmol) and N,O-bis(trimethylsilyl)acetamide (2.5 mL, 10 mmol) in a 20 mL seal tube was heated at 240° C. for 48 hours. The reaction was then cooled to room temperature. Diethyl ether (60 mL) was added, and the organic layer was washed with HCl (3N, 20 mL). The organic layer was separated and the solvent was removed. The residue was dissolved in MeOH (10 mL) and HCl (3N, 2 mL) and stiffed at room temperature for 30 minutes. Diethyl ether (80 mL) was added, and the organic layer was washed with NaHCO3 (30 mL) and brine (15 mL). The organic layer was dried over MgSO4. After filtration, the solvent was removed, and the residue was purified by CombiFlash® silica gel column chromatography, eluting with hexane/EtOAc, 95/5 to give 26.3 (0.15 g, yield 30%). 1H NMR (500 MHz, CDCl3) δ ppm 7.90 (1H, d, J=2.2 Hz), 7.80 (1H, dd, J=8.3, 2.0 Hz), 6.81 (1H, d, J=8.3 Hz), 5.99 (1H, dd, J=17.6, 10.5 Hz), 5.77 (1H, s), 5.18 (1H, dd, J=10.5, 1.0 Hz), 5.08 (1H, d, J=17.6 Hz), 3.82 (3H, s), 1.89-2.03 (4H, m), 1.56-1.78 (4H, m). MS ESI (neg.) m/e: 245.1 (M−H)+.

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