Ethyl Acetate → methyl 3-methyl-2-oxo-2,3-dihydro-1H-benzo[d]imidazole-5-carboxylate

HRID 2404282Notes

Reaction equation

HRID 2404282 reaction equation
[C:1](C1NC=CN=1)(C1NC=CN=1)=[O:2].[NH2:13][C:14]1[CH:23]=[CH:22][C:17]([C:18]([O:20][CH3:21])=[O:19])=[CH:16][C:15]=1[NH:24][CH3:25].C(OCC)(=O)C>O1CCCC1>[CH3:25][N:24]1[C:15]2[CH:16]=[C:17]([C:18]([O:20][CH3:21])=[O:19])[CH:22]=[CH:23][C:14]=2[NH:13][C:1]1=[O:2]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 5250894Bis-(1H-imidazol-2-YL)-methanone2×HCID 57835341Methyl 4-amino-3-(methylamino)benzoate

Product 1

HCID 67151300methyl 3-methyl-2-oxo-2,3-dihydro-1H-benzo[d]imidazole-5-carboxylateYield 64.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Add carbonyl diimidazole (567 mg, 3.50 mmol) to a solution of methyl 4-amino-3-(methylamino)benzoate (586 mg. 3.19 mmol) in tetrahydrofuran (20 mL) at room temperature. Stir the yellow solution at room temperature for 16 hours. Add carbonyl diimidazole (500 mg, 0.96). Stir at room temperature for 4 hours. Add ethyl acetate (75 mL). Wash with 10% citric acid (5 mL), 1N sodium hydroxide (5 mL), and brine (5 mL). Dry the organics over magnesium sulfate, filter, concentrate, and dry under high vacuum to yield a crude yellow solid (690 mg, 100%). Triturate this crude solid with ethyl acetate (10 mL). Filter the precipitate and dry under high vacuum to yield methyl 3-methyl-2-oxo-2,3-dihydro-1H-benzo[d]imidazole-5-carboxylate (422 mg, 64%). 1H NMR (400 MHz, CDCl3) δ ppm 3.46 (s, 3H), 3.92 (s, 3H), 7.12 (d, J=8.21 Hz, 1H), 7.68 (s, 1H), 7.84 (dd, J=8.31, 1.47 Hz, 1H), 9.87-10.03 (m, 1H).

Workup

  1. stirringStir at room temperature for 4 hours
  2. washWash with 10% citric acid (5 mL), 1N sodium hydroxide (5 mL), and brine (5 mL)
  3. dry with materialDry the organics over magnesium sulfate
  4. filtrationfilter
  5. concentrationconcentrate
  6. customdry under high vacuum
  7. customto yield a crude yellow solid (690 mg, 100%)
  8. customTriturate this crude solid with ethyl acetate (10 mL)
  9. filtrationFilter the precipitate
  10. customdry under high vacuum

Sources & evidence

ORD record
ord-4fa189988f3e4a2c960022e9cd06199b
Source dataset
uspto-grants-2014_08
Patent number
US08802690B2

Reaction notes

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