Reaction #83992

Reaction equation

Phosphorus oxychloride

N-methylformanilide

2-Methyl resorcinol

→

product

Yield 57.0%

2,4-Dihydroxy-3-methylbenzaldehyde

Yield 57.0%

Solvents

ether

Conditions

Workup

1. 1
   Temperaturecooled in ice
2. 2
   Temperatureto warm to room temperature
3. 3
   workup.STIRRINGwhile stirring overnight
4. 4
   FiltrationThe precipitated intermediate product was collected by filtration
5. 5
   Washrinsed with ether (3×)
6. 6
   workup.DISSOLUTIONby dissolving in a mixture of acetone (250 mL) and water (250 mL)
7. 7
   workup.STIRRINGstirring for 30 minutes
8. 8
   workup.ADDITIONWater (2 L) was added
9. 9
   Temperatureto cool
10. 10
    OtherThis was recrystallized a second time from water (4 L)

Procedure

Phosphorus oxychloride (80 mL, 0.86 mol) was added to a stirred mixture of N-methylformanilide (102 mL, 0.82 mol) in ether (250 mL). The mixture was stirred for 1 hour at room temperature and then cooled in ice. 2-Methyl resorcinol (Aldrich, 100 g, 0.81 mol) was added and the mixture was allowed to warm to room temperature while stirring overnight. The precipitated intermediate product was collected by filtration and rinsed with ether (3×). The intermediate was hydrolyzed by dissolving in a mixture of acetone (250 mL) and water (250 mL) and stirring for 30 minutes. Water (2 L) was added, the mixture was brought to a boil, and then allowed to cool and deposit crystalline product. This was recrystallized a second time from water (4 L) to afford pure product (70 g, 57%). M.p. 150° C. (Lit. 152°-3° C. [W. Baker et al., J. Chem. Soc. 2834-5 (1949)⟧

Source