Trifluoroacetic acid → 4-Methylbenzimidazole

HRID 1582296Notes

Reaction equation

HRID 1582296 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[CH:4][C:3]=1[CH3:9].[CH3:10]OC(OC)OC.FC(F)(F)C(O)=O>C(Cl)Cl>[CH3:9][C:3]1[C:2]2[N:1]=[CH:10][NH:8][C:7]=2[CH:6]=[CH:5][CH:4]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 9005Trimethyl orthoformateHCID 175932,3-Diaminotoluene

Product 1

HCID 15193414-Methylbenzimidazole

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of 2,3-diaminotoluene (1.00 g, 8.2 mmol) in CH2Cl2 (82 mL) was added trimethylorthoformate (4.5 mL, 41 mmol) and trifluoroacetic acid (0.32 mL, 4.1 mmol) and the mixture stirred at room temperature for 24 h after which the reaction mixture was diluted with CH2Cl2 (200 mL), and washed consecutively with saturated aqueous NaHCO3 (40 mL) and H2O (40 mL). The aqueous layers were reextracted with CH2Cl2 (2×100 mL). The combined organic extracts were dried over MgSO4 and concentrated to a rusty brown solid (1.07 g, 97%)., 1H NMR (300 MHz, CDCl3) 6 8.08 (s, 1H), 7.49 (d, 1H, J=8.1 Hz), 7.23-7.18 (m, 1H), 7.10 (d, 1H, J=7.5 Hz), 2.64 (s, 3H).

Workup

  1. washwashed consecutively with saturated aqueous NaHCO3 (40 mL) and H2O (40 mL)
  2. dry with materialThe combined organic extracts were dried over MgSO4
  3. concentrationconcentrated to a rusty brown solid (1.07 g, 97%)

Sources & evidence

ORD record
ord-eb561943f543431fa4a5081bb116247f
Source dataset
uspto-grants-2004_05
Patent number
US06734191B2

Reaction notes

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