反应 #1981268
相关文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US07723537B2
反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: Concentrated sulfuric acid (1.2 mL, 43 mmol) was added to a solution of 7-hydroxy-3,4-dihydro-4-methylcoumarin (B1) (75.8 g, 430 mmol) in methanol (1 L) at room temperature and the solution stirred for about 16 hours. At this time, TLC (8% methanol:chloroform) showed the clean formation of product at the expense of starting material. The solution was neutralized with 7% NaHCO3 solution (50 ml) and the majority of the solvent (750 ml) removed under reduced pressure. The solution was diluted with ethyl acetate (1 L), washed successively with saturated NaHCO3: saturated NaCl (1:1, 200 ml), saturated NaCl (2×200 ml), dried (Na2SO4), filtered and the solvent removed to give an orange oil. Further purification by filtering through a short pad of silica gel and eluting with 5% methanol in chloroform afforded pure product as a pale orange gel (87 g, 98%): 1H NMR (DMSO-d6) d 1.13 (d, JJ=7.0, 3H), 2.42 (dd, JJ=15.0, 8.9, 1H), 2.58 (dd, JJ=15.0, 5.8, 1H), 3.37 (m, 1H), 3.55 (s, 3H), 6.15 (dd, JJ=8.6, 2.4, 1H), 6.28 (d, JJ=2.4, 1H), 6.84 (d, JJ=8.2, 1H), 8.93 (s, 1H), 9.11 (s, 1H); 13C NMR (DMSO-d6) d 20.16, 29.09, 40.77, 51.00, 102.55, 106.02, 122.09, 127.04, 155.18, 156.27, 172.55; m/z (EI; TMS derivatized; M+) 354; IR (neat; cm−1) 3384.5, 2969.3, 1708.9, 1621.0, 1606.3, 1518.4, 1454.9, 1367.0, 1303.5, 1220.4, 1166.7, 1108.1, 976.2, 839.4, 810.1. the majority of the solvent (750 ml) removed under reduced pressure The solution was diluted with ethyl acetate (1 L) washed successively with saturated NaHCO3 saturated NaCl (1:1, 200 ml), saturated NaCl (2×200 ml), dried (Na2SO4) filtered the solvent removed to give an orange oil Further purification by filtering through a short pad of silica gel eluting with 5% methanol in chloroform afforded pure product as a pale orange gel (87 g, 98%)
来源 ID: ord-357963b07aa441c99e4082efedfc6491