O-Phenylenediamine → 95242-09-4

HRID 462674Notes

Reaction equation

HRID 462674 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[CH3:9][C:10]([CH3:18])([CH2:14][C:15](O)=O)[C:11]([OH:13])=[O:12].[OH-].[Na+]>Cl.O>[CH3:9][C:10]([CH3:18])([CH2:14][C:15]1[NH:8][C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=2[N:7]=1)[C:11]([OH:13])=[O:12]

Participants

6

Reactant 3

HCID 7243O-PhenylenediamineHCID 117012,2-Dimethylsuccinic acidHCID 14798Sodium Hydroxide

Product 1

HCID 499410995242-09-4Yield 82.5%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent

Procedure

A solution of o-phenylenediamine (5.4 g, 0.05 mole) and 2,2-dimethylsuccinic acid (7.5 g, 0.05 mole) in 50 mL of 4.8 N HCl was refluxed without condenser until the total volume was reduced to about 20 mL. Evaporation at 100° and 40 torr afforded a green paste which was taken up in 100 mL H2O and made alkaline (pH 9) with 20% NaOH. The mixture was filtered removing tarry matter and the clear yellow filtrate was concentrated, cooled and the pH adjusted to about 6 by addition of acetic acid. A light yellow solid precipitated and was isolated by filtration and dried in air to give 9 g of α,α-dimethyl-1H-2-benzimidazolepropanoic acid, m.p. 223°-226° (dec). Recrystallization from acetonitrile-methyl ethyl ketone-methanol (30-30-40) afforded 6.7 g (61%) of colorless needles, m.p. 266°-267° (dec).

Workup

  1. customEvaporation at 100°
  2. custom40 torr afforded a green paste which
  3. filtrationThe mixture was filtered
  4. customremoving tarry matter
  5. concentrationthe clear yellow filtrate was concentrated
  6. temperaturecooled
  7. additionthe pH adjusted to about 6 by addition of acetic acid
  8. customA light yellow solid precipitated
  9. customwas isolated by filtration
  10. customdried in air

Sources & evidence

ORD record
ord-337982b7376d4006b0475cd63a17353b
Source dataset
uspto-grants-1985_05
Patent number
US04517188

Reaction notes

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