O-Phenylenediamine → 1,3-Dihydro-1-(1-methylvinyl)-2H-benzimidazol-2-one

HRID 266693Notes

Reaction equation

HRID 266693 reaction equation
[OH-:1].[K+].C(OC)(=O)[CH2:4][C:5]([CH3:7])=O.[NH2:11][C:12]1[CH:18]=[CH:17][CH:16]=[CH:15][C:13]=1[NH2:14].O.[CH3:20]O>C1(C)C(C)=CC=CC=1>[C:5]([N:11]1[C:12]2[CH:18]=[CH:17][CH:16]=[CH:15][C:13]=2[NH:14][C:20]1=[O:1])([CH3:7])=[CH2:4]

Participants

6

Reactant 4

HCID 7243O-PhenylenediamineHCID 7757Methyl acetoacetateHCID 14797Potassium HydroxideHCID 22242641Methanol--water (1/1)

Product 1

HCID 1002781,3-Dihydro-1-(1-methylvinyl)-2H-benzimidazol-2-one

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent2×

Conditions

Temperature
120 °C

Procedure

1 ml of a 47% potassium hydroxide solution and then 530 mmol of methyl acetoacetate in solution in 20 ml of xylene are added to 500 mmol of 2-aminoaniline in 150 ml of xylene heated to 120° C. The whole mixture is heated and the water/methanol mixture formed is removed by means of a Dean and Stark apparatus. The whole mixture is then brought to reflux for 3 hours. After cooling to 40° C., 83 ml of 47% potassium hydroxide and 55 ml of water are added. The alkaline aqueous phase is neutralized with acetic acid. The expected product then crystallizes; it is filtered off, washed with water and dried.

Workup

  1. temperatureThe whole mixture is heated
  2. customis removed by means of a Dean and Stark apparatus
  3. temperatureto reflux for 3 hours
  4. temperatureAfter cooling to 40° C.
  5. addition83 ml of 47% potassium hydroxide and 55 ml of water are added
  6. customThe expected product then crystallizes
  7. filtrationit is filtered off
  8. washwashed with water
  9. customdried

Sources & evidence

ORD record
ord-65737e6df003433cae40748e4b4c1aa9
Source dataset
uspto-grants-1997_07
Patent number
US05652246

Reaction notes

Loading…