Benzyl chloroformate → 6-Methyl 1-(phenylmethyl) 2,3-dihydro-2-oxo-1H-benzimidazole-1,6-dicarboxylate

HRID 1861864Notes

Reaction equation

HRID 1861864 reaction equation
C(OC([N:8]1[C:12]2[CH:13]=[CH:14][C:15]([C:17]([O:19][CH3:20])=[O:18])=[CH:16][C:11]=2[NH:10][C:9]1=[O:21])=O)(C)(C)C.C(N(CC)C(C)C)(C)C.Cl[C:32]([O:34][CH2:35][C:36]1[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=1)=[O:33]>C(Cl)Cl.C(OCC)(=O)C>[O:21]=[C:9]1[NH:8][C:12]2[CH:13]=[CH:14][C:15]([C:17]([O:19][CH3:20])=[O:18])=[CH:16][C:11]=2[N:10]1[C:32]([O:34][CH2:35][C:36]1[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=1)=[O:33]

Participants

6

Reactant 3

HCID 10387Benzyl chloroformateHCID 81531DiisopropylethylamineHCID 18621653HCID 18621653, compound

Product 1

HCID 186216456-Methyl 1-(phenylmethyl) 2,3-dihydro-2-oxo-1H-benzimidazole-1,6-dicarboxylateYield 89%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

Part 1. To a chilled solution of methyl 1-[(tert-butyl)oxycarbonyl]-2-oxo-(3H)—benzimidazole-5-carboxylate (0.37 g, 1.28 mmol) in CH2Cl2 (8 mL) and N,N-diisopropylethylamine (0.23 mL, 1.3 mmol) was added a solution of benzyl chloroformate (0.208 mL, 1.46 mmol) in CH2Cl2 (2 mL). The reaction was stirred at room temperature for 2.5 hr, diluted with ethyl acetate, washed with water and brine, dried over sodium sulfate and concentrated in vacuo. This residue was dissolved in CH2Cl2 (9 mL) and treated with neat trifluoroacetic acid (2 mL) at 0° C. for 40 min, diluted with ethyl acetate, washed with 5% NaHCO3, water and brine, dried over sodium sulfate and concentrated to yield methyl 2-oxo-3-[benzyloxycarbonyl]-(3H)—benzimidazole-5-carboxylate (0.37 g, 89%) as an off-white solid. 1H NMR (CDCl3) δ: 3.51 (s, 3H); 5.14 (s, 2H); 6.67-6.69 (d, 1H); 6.97-7.06 (m, 5H); 7.17-7.18 (d, 1H); 7.51-7.53 (d, 1H); 8.07 (s, 1H). ES-MS (M+Na)+=349.0.

Workup

  1. washwashed with water and brine
  2. dry with materialdried over sodium sulfate
  3. concentrationconcentrated in vacuo
  4. dissolutionThis residue was dissolved in CH2Cl2 (9 mL)
  5. additiontreated with neat trifluoroacetic acid (2 mL) at 0° C. for 40 min
  6. additiondiluted with ethyl acetate
  7. washwashed with 5% NaHCO3, water and brine
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-b2022f2451fe47c682c029998a42d895
Source dataset
uspto-grants-2003_03
Patent number
US06534535B1

Reaction notes

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