反应详情

To a slurry of 3-cyclopentyl-p-anisic acid (5.0 g, 22.7 mmol, RN-59216-82-9) in anhydrous methylene chloride (60 mL) was added oxalyl chloride (2.4 mL, 27.2 mmol) and N,N-dimethylformamide (2 drops) at room temperature under nitrogen. After stirring for 1.5 h the reaction mixture was concentrated under reduced pressure. The residue was dissolved in carbon disulfide (32 mL) and the resulting solution was added to 2,3-dimethyl-5-benzylthiophene (5.1 g, 25.0 mmol). At −78° C. under nitrogen, tin(IV) chloride (2.9 mL, 25.0 mmol) was added, and the reaction mixture was then stirred at room temperature for 4 h. The solution was poured onto a mixture of ice and water (200 mL) and extracted with diethyl ether (200 mL). The diethyl ether layer was washed twice with sodium bicarbonate (50 mL) and once with brine (50 mL). Concentration under reduced pressure and chromatography with petroleum ether:ethyl acetate (95:5) gave the title compound as an amber oil (4.8 g, 52%): (DMSO-d6): δ7.61-7.54 (m, 2H), 7.24-7.14 (m, 3H), 7.08-7.02 (m, 3H), 3.87 (s, 3H), 3.84 (s, 2H), 3.42-3.30 (m, 1H), 2.26 (s, 3H), 2.00-1.85 (m, 2H), 1.81 (s, 3H), 1.74-1.58 (m, 4H), 1.48-1.36 (m, 2H); MS(EI): [M+] 404; Anal. Calc. for C26H28O2S: C, 77.19; H, 6.98; N, 0.00. Found: C, 76.26; H, 7.24; N, 0.04.

1. concentrationwas concentrated under reduced pressure
2. dissolutionThe residue was dissolved in carbon disulfide (32 mL)
3. stirringthe reaction mixture was then stirred at room temperature for 4 h
4. extractionextracted with diethyl ether (200 mL)
5. washThe diethyl ether layer was washed twice with sodium bicarbonate (50 mL) and once with brine (50 mL)
6. concentrationConcentration under reduced pressure and chromatography with petroleum ether:ethyl acetate (95:5)