Reaction #1135826

Reaction equation

2-Methylresorcinol

3,4-dimethoxyphenylacetic acid

boron trifluoride diethyl etherate

BF3.OEt2

→

1-(2,4-dihydroxy-3-methyl-phenyl)-2-(3,4-dimethoxy-phenyl) ethanone

Conditions

Workup

1. 1
   OtherThe round bottom flask was attached to a condenser
2. 2
   Otherplaced in an oil bath
3. 3
   OtherA yellow solid formed at 75 minutes
4. 4
   TemperatureThe reaction was heated for a further 10 minutes
5. 5
   Temperaturecooled to room temperature
6. 6
   FiltrationThe yellow solid was collected by suction filtration
7. 7
   Washwashed with distilled water (200 ml)
8. 8
   Otherto remove any excess BF3.OEt2 present
9. 9
   OtherThe solid was dried on a freeze dryer for 24 hours (6.303 g, 43%)

Procedure

2-Methylresorcinol (6.285 g, 1 equivalent) and 3,4-dimethoxyphenylacetic acid (9.251 g, 1 equivalent) were added to a round bottom flask. The round bottom flask was attached to a condenser and placed in an oil bath, the whole system was kept under nitrogen. Distilled boron trifluoride diethyl etherate, BF3.OEt2 (42 ml, 5 equiv.) was added to the mixture while stirring. The mixture was refluxed (110° C.). A yellow solid formed at 75 minutes indicating that the reaction had gone to completion. The reaction was heated for a further 10 minutes and cooled to room temperature. The yellow solid was collected by suction filtration and washed with distilled water (200 ml) to remove any excess BF3.OEt2 present. 1H NMR in d-DMSO indicated the yellow solid was 1-(2,4-dihydroxy-3-methyl-phenyl)-2-(3,4-dimethoxy-phenyl) ethanone in >95% purity. The solid was dried on a freeze dryer for 24 hours (6.303 g, 43%).

Source