Acetic Acid → N,N'-Bis(2-methylphenyl)ethanimidamide

HRID 741772Notes

Reaction equation

HRID 741772 reaction equation
[NH2:1][C:2]1[C:3]([CH3:8])=[CH:4][CH:5]=[CH:6][CH:7]=1.C(O[CH2:18][CH3:19])(OCC)(OCC)C.[ClH:20].[C:21](O)(=O)[CH3:22]>CCOCC>[ClH:20].[CH3:8][C:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[NH:1][C:2](=[N:1][C:22]1[CH:21]=[CH:8][CH:3]=[CH:4][C:18]=1[CH3:19])[CH3:7]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 313Hydrochloric AcidHCID 7242O-ToluidineHCID 66221Triethyl orthoacetate

Product 2

HCID 313Hydrochloric AcidHCID 252230N,N'-Bis(2-methylphenyl)ethanimidamideYield 88%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

According to literature ((Taylor, E. C. et al., J. Org. Chem. 28:1108 (1963)), a solution of o-toluidine (4.28 g, 40.0 mmol) and triethyl orthoacetate (3.24 g, 290 mmol) in acetic acid (1 ml) was heated to reflux for 2 h. Volatile compounds were distilled off (120°-140°, 20 mm) and the solid residue was extracted with ether (total of 50 ml) in presence of 1N solution of Na2CO3 in water (100 ml). Two fold recrystallization from hexane-5% toluene gave white but still impure amidine (1.85 g, 38%); Mp 65°-68° (Lit (Taylor et al., supra) 70°, Lit (Barluenga, J. et al., Perkin 1 2732 (1980) 134°-135°). On chromatography with hexanes-ether 2:1 some unreacted o-toluidine was removed as the least polar fraction (TLC ether 0.75). Intermediate fractions contained colorless N-tolyl acetimidate. Almost pure amidine (TLC ether 0.46) was eluted with hexanes-ether 1:1. This compound was further purified by chromatography with THF-hexanes 1:1 then 1:0 and filtration of the eluents through celite for the removal of turbid matter. The addition of HCl gas saturated ether (5 ml) to a solution of the amidine (313 mg, 1.31 mmol) in ether (10 ml) gave the new hygroscopic, hydrochloride of the title compound (318 mg, 88%), Mp 237°-239°.

Workup

  1. temperatureto reflux for 2 h
  2. distillationVolatile compounds were distilled off (120°-140°, 20 mm)
  3. extractionthe solid residue was extracted with ether (total of 50 ml) in presence of 1N solution of Na2CO3 in water (100 ml)
  4. customTwo fold recrystallization from hexane-5% toluene
  5. customgave white
  6. customLit (Taylor et al., supra) 70°, Lit (Barluenga, J. et al., Perkin 1 2732 (1980) 134°-135°)
  7. customOn chromatography with hexanes-ether 2:1 some unreacted o-toluidine was removed as the least polar fraction (TLC ether 0.75)
  8. washAlmost pure amidine (TLC ether 0.46) was eluted with hexanes-ether 1:1
  9. customThis compound was further purified by chromatography with THF-hexanes 1:1
  10. filtration1:0 and filtration of the eluents through celite
  11. customfor the removal of turbid matter

Sources & evidence

ORD record
ord-43021db28a754f3cbdc0256ea8461c57
Source dataset
uspto-grants-1996_09
Patent number
US05552443

Reaction notes

Loading…