Reaktion #1805

Reaktionsgleichung

water

1-carbomethoxy-6-methoxy-2-tetralone

resorcinol

phosphorus oxychloride

→

title compound

Ausbeute 70.8%

2-Methoxy-8-hydroxy-11,12-dihydro-5H-benzo[b]naphtho[2,1-d]pyran-5-one

Ausbeute 70.8%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling to room temperature
2. 2
   Filtrationfiltered
3. 3
   Waschenrinsing the precipitate with ether
4. 4
   SonstigeThe filtrate layers were separated
5. 5
   Extraktionthe aqueous layer was extracted with ethyl acetate (3×500 mL)
6. 6
   Trocknenthe combined organic layers were dried (sodium sulfate)
7. 7
   Einengenconcentrated
8. 8
   SonstigeRecrystallization of the residue from methanol

Vorschrift

To a solution of 1-carbomethoxy-6-methoxy-2-tetralone (see, Colvin, Martin, and Shroot, Chemistry and Industry, 2130 (1966)) (18.0 g, 76.8 mmol) and resorcinol (8.9 g, 80.7 mmol) stirring at ambient temperature in toluene (450 mL) was added phosphorus oxychloride (12.0 g, 7.3 mL, 18.3 mmol) dropwise, and the mixture warmed to 80° C. for 12 h. After cooling to room temperature, the mixture was poured into water (500 mL) and filtered, rinsing the precipitate with ether. The filtrate layers were separated, the aqueous layer was extracted with ethyl acetate (3×500 mL), and the combined organic layers were dried (sodium sulfate) and concentrated. Recrystallization of the residue from methanol provided 16.0 g of the title compound as a yellow solid, mp 244-249 d°C.: 1 H NMR (300 MHz, DMSO-d6) d 10.55 (br s, 1H), 8.24 (d, J=8.6 Hz, 1H), 7.75 (d, J=8.7 Hz, 1H), 6.6-7.0 (m, 4H), 3.76 (s, 3H), 2.8-3.0 (m, 4H); 13C NMR (125 MHz, DMSO-d6) d 170.3, 160.3, 158.3, 158.1, 153.3, 147.7, 137.5, 127.4, 125.8, 122.5, 114.5, 112.6, 112.4, 110.9, 101.4, 54.6, 26.3, 22.7; IR (KBr) 3250, 1676, 1618 cm-1 ; MS (FD+) m/e 294 (M+); Anal. calc'd. for C18H14O4 : C, 73.45; H, 4.80. Found: C, 73.15; H, 4.86.

Quelle