Reacción #1805

Ecuación de reacción

water

1-carbomethoxy-6-methoxy-2-tetralone

resorcinol

phosphorus oxychloride

→

title compound

Rendimiento 70.8%

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

Rendimiento 70.8%

Disolventes

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaAfter cooling to room temperature
2. 2
   Filtraciónfiltered
3. 3
   Lavadorinsing the precipitate with ether
4. 4
   OtroThe filtrate layers were separated
5. 5
   Extracciónthe aqueous layer was extracted with ethyl acetate (3×500 mL)
6. 6
   Secadothe combined organic layers were dried (sodium sulfate)
7. 7
   Concentraciónconcentrated
8. 8
   OtroRecrystallization of the residue from methanol

Procedimiento

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.

Fuente