反応 #3747852
関連文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US08759390B2
反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
実験手順: A mixture of methyl 3-(2-hydroxyphenyl)-3-oxopropanoate (prepared according to Cushman, M. et al., J. Med. Chem. 1991, 34, 798; 500 mg, 2.56 mmol) and 3,4-dichlorobenzaldehyde (496 mg, 2.83 mmol) in isopropanol (5.0 mL) was treated with piperidine (25 μl, 257 μmol) and acetic acid (15 μl, 257 μmol) and then heated to reflux for 20 h. At the conclusion of this period, the mixture was cooled on ice, causing a gum to separate from the solution. The mixture was treated with a small amount of water and heated until homogeneous. On slow cooling to rt, a solid formed, which was collected by filtration and dried under vacuum to provide racemic methyl 2-(3,4-dichlorophenyl)-4-oxochroman-3-carboxylate as an off-white powder (496 mg, 55%). An additional sample (57 mg, 6%) was obtained by partial concentration of the filtrate. The NMR indicated predominantly the enolic form. 1H NMR (400 MHz, CDCl3) δ ppm 3.78 (s, 3 H) 6.18 (s, 1 H) 6.81 (dd, J=8.1, 1.0 Hz, 1H) 6.99 (td, J=7.4, 1.0 Hz, 1 H) 7.19 (dd, J=8.4, 1.8 Hz, 1 H) 7.31 (m, 1 H) 7.34 (d, J=8.1 Hz, 1 H) 7.43 (d, J=2.0 Hz, 1 H) 7.69 (dd, J=7.9, 1.8 Hz, 1 H) 12.28 (br. s, 1H). High resolution mass spectrum m/z found 373.0016, calcd 373.0010 (M+Na)+. heated to reflux for 20 h At the conclusion of this period, the mixture was cooled on ice to separate from the solution The mixture was treated with a small amount of water heated until homogeneous a solid formed which was collected by filtration dried under vacuum
ソース ID: ord-35312914542f473fa6f7bf1f7d19f488