Reaction #470410

Reaction equation

ethanol

4′,7-Dihydroxyisoflav-3-ene

benzylamine

formaldehyde

dehydroequol

ethanol

→

title compound

4-(3-Benzyl-2,3,4,8-tetrahydrochromeno[6,7-e][1,3]oxazin-7-yl)phenol

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was refluxed for approximately 7 hours
2. 2
   Temperatureafter cooling to room temperature the volume
3. 3
   Concentrationwas concentrated in vacuo
4. 4
   workup.WAITThe mixture was left in the fridge
5. 5
   Otherto crystallise
6. 6
   OtherThe yellow solid was collected under suction
7. 7
   Otherthe filtrate evaporated to dryness

Procedure

4′,7-Dihydroxyisoflav-3-ene (0.47 g, 1.97 mmol) was dissolved in ethanol (ca. 40 mL) and heated to 80-90° C. A solution of benzylamine (0.44 mL, 3.5 mmol) and 37% formaldehyde (0.35 mL, 12.7 mmol) in ethanol (ca. 20 mL) was added to the dehydroequol solution. The reaction mixture was refluxed for approximately 7 hours and after cooling to room temperature the volume was concentrated in vacuo. The mixture was left in the fridge to crystallise. The yellow solid was collected under suction and the filtrate evaporated to dryness to obtain a second crop of the title compound, (combined yield 0.17 g, 23%).

Source