Reacción #432178

Ecuación de reacción

tetrahydrofuran

1,8-dichloroanthraquinone

18-crown-6

sodium methoxide

→

1,8-dimethoxyanthraquinone

Rendimiento 50.0%

Disolventes

EtOAc toluene

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroA 5-liter round-bottom flask equipped with an overhead stirrer
2. 2
   Temperaturathermocouple, and reflux condenser with a nitrogen/vacuum outlet
3. 3
   OtroThis solution was deoxygenated
4. 4
   Temperaturaheated until a clear solution
5. 5
   Otrowas obtained
6. 6
   TemperaturaThe reaction mixture was heated
7. 7
   TemperaturaThe reaction was cooled overnight in an ice bath
8. 8
   Otrothe crystallized product isolated by filtration (82% crude yield)
9. 9
   OtroThis material was recrystallized from 1000 mL of toluene

Procedimiento

A 5-liter round-bottom flask equipped with an overhead stirrer, thermocouple, and reflux condenser with a nitrogen/vacuum outlet was charged with 1200 mL of tetrahydrofuran, 138.5 grams of 1,8-dichloroanthraquinone, and 35.6 grams of 18-crown-6. This solution was deoxygenated, stirred under nitrogen, and heated until a clear solution was obtained. A solution of 165.0 grams of sodium methoxide in 1000 mL of methanol (prepared from sodium metal) was then added over a period of 30 min. The reaction mixture was heated at reflux for 24 hours, at which time TLC (silica gel, 1:1 EtOAc/toluene) indicated that the reaction was complete. The reaction was cooled overnight in an ice bath and the crystallized product isolated by filtration (82% crude yield). This material was recrystallized from 1000 mL of toluene to afford 1,8-dimethoxyanthraquinone in an overall yield of 50%.

Fuente