反应详情

温度

0 °C

m-Chloroperoxybenzoic acid [1.2 g, ALDRICH, 50% (remainder 3-chlorobenzoic acid and water), ca. 7.0 mmol] was added in portions over 0.25 h to a magnetically stirred mixture of 2-[(4-isopropoxy-3-methoxy-phenyl)ethynyl]-5-isopropoxy-4-methoxybenzaldehyde (2.20 g, 5.75 mmol) and KHCO3 (1.73 g, 17.3 mmol) in CH2Cl2 (50 mL) maintained at 0° C. (ice-bath). The resulting slurry was stirred for a further 1 h between 0° C. and 18° C. then filtered through Celite® and the solids thus retained rinsed with CH2Cl2 (1×50 mL). The combined filtrates were concentrated under reduced pressure and the residue treated with NH3 (30 ml of a saturated methanolic solution). After 1 h at 18° C. the reaction mixture was concentrated under reduced pressure and the residue redissolved in CH2Cl2 (200 mL) then concentrated on to silica gel (8 g, 400-200 mesh). The resulting powder was loaded on top of a column of silica (40-10 mesh TLC grade, 10 cm wide×5 cm long) and eluted with 2:1, 1:1 and 1:2 hexane/CH2Cl2 then neat CH2Cl2 (250 ml of each). The appropriate fractions (Rf 0.3 in 1:2 hexane/CH2Cl2) were concentrated under reduced pressure to give the title compound (1.97 g, 92%) as white crystalline masses, mp 130-1° C. IR (KBr disc, cm−1) 3404, 2981, 2935, 1620, 1573, 1513, 1467, 1450, 1418, 1383, 1373, 1330, 1269, 1240, 1214, 1166, 1135, 1113, 951. 1H NMR (300 MHz, CDCl3) δ 7.03 (dd, J=1.8, 8.4 Hz, 1H), 7.00 (d, J=2.1 Hz, 1H), 6.87 (s, 1H), 6.81 (d, J=8.4 Hz, 1 H), 6.53 (s, 1H), 5.81 (s, 1H), 4.52 (septet, J=6.0 Hz, 2H), 3.82 (s, 3H), 3.78 (s, 3H), 1.35 (d, J=6.0 Hz, 12H). 13C NMR+APT (75.5 MHz, CDCl3) δ 151.8 (C), 149.7 (C), 149.3 (C), 147.8 (C), 143.6 (C), 124.6 (CH), 115.0 (C), 114.7 (CH), 114.6 (CH), 114.3 (CH), 102.0 (CH), 100.1 (C), 94.7 (C), 82.2 (C), 71.1 (CH), 71.0 (CH), 56.4 (CH3), 55.7 (CH3), 21.9 (CH3), 21.8 (CH3). MS (70 eV) m/z (%): 370 (M+·), 355 (2, M+·-CH3), 328 (18, M+·-CH(CH3)2], 327 (20, M+·CH2CHCH3), 286 (100, M+·-2×CH2CHCH3), 271 (42, M+·-2×CH2CHCH3—CH3). Anal. Calcd for C22H26O5 C, 71.33; H, 7.07. Found: C, 70.91; H, 7.24.

1. filtrationthen filtered through Celite®
2. washthe solids thus retained rinsed with CH2Cl2 (1×50 mL)
3. concentrationThe combined filtrates were concentrated under reduced pressure
4. additionthe residue treated with NH3 (30 ml of a saturated methanolic solution)
5. concentrationAfter 1 h at 18° C. the reaction mixture was concentrated under reduced pressure
6. dissolutionthe residue redissolved in CH2Cl2 (200 mL)
7. concentrationthen concentrated on to silica gel (8 g, 400-200 mesh)
8. washeluted with 2:1, 1:1 and 1:2 hexane/CH2Cl2
9. concentrationThe appropriate fractions (Rf 0.3 in 1:2 hexane/CH2Cl2) were concentrated under reduced pressure