Reaction #1244259

Reaction equation

methyl ethyl ketone

quinizarin

potassium carbonate

ethyl sulfate

→

1,4-Diethoxyanthraquinone

Conditions

Workup

1. 1
   FiltrationThe reaction was filtered hot through Celite
2. 2
   OtherThe solution was evaporated on a rotary evaporator until crystallization
3. 3
   TemperatureAfter cooling in an ice bath
4. 4
   Filtrationthe crystals were filtered
5. 5
   Washrinsed with Et2O
6. 6
   Othersucked dry
7. 7
   Otherdried overnight in a vacuum oven at 70° C

Procedure

A mixture of quinizarin (20.0 g, 83.5 mmol), potassium carbonate (76 g, 550 mmol) and ethyl sulfate (38.6 g, 250 mmol) was refluxed in methyl ethyl ketone (MEK, 950 mL) for 24 hrs. The reaction was filtered hot through Celite using additional hot MEK. The solution was evaporated on a rotary evaporator until crystallization began, then the reaction was allowed to sit overnight. After cooling in an ice bath, the crystals were filtered, rinsed with Et2O, sucked dry, then dried overnight in a vacuum oven at 70° C. The yield was 14.0 g (57%) of yellow/orange crystals.

Source