Réaction #1805

Équation de réaction

water

1-carbomethoxy-6-methoxy-2-tetralone

resorcinol

phosphorus oxychloride

→

title compound

Rendement 70.8%

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

Rendement 70.8%

Solvants

toluene

Conditions de réaction

Traitement

1. 1
   TempératureAfter cooling to room temperature
2. 2
   Filtrationfiltered
3. 3
   Lavagerinsing the precipitate with ether
4. 4
   AutreThe filtrate layers were separated
5. 5
   Extractionthe aqueous layer was extracted with ethyl acetate (3×500 mL)
6. 6
   Séchagethe combined organic layers were dried (sodium sulfate)
7. 7
   Concentrationconcentrated
8. 8
   AutreRecrystallization of the residue from methanol

Mode opératoire

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.

Source