Hydrochloric Acid → 4-(2,3-Dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidineacetic acid

HRID 1760191Notes

Reaction equation

HRID 1760191 reaction equation
[O:1]=[C:2]1[N:6]([CH:7]2[CH2:12][CH2:11][N:10]([CH2:13][C:14]([O:16]CC)=[O:15])[CH2:9][CH2:8]2)[C:5]2[CH:19]=[CH:20][CH:21]=[CH:22][C:4]=2[NH:3]1.[OH-].[Na+].Cl>CO>[O:1]=[C:2]1[N:6]([CH:7]2[CH2:12][CH2:11][N:10]([CH2:13][C:14]([OH:16])=[O:15])[CH2:9][CH2:8]2)[C:5]2[CH:19]=[CH:20][CH:21]=[CH:22][C:4]=2[NH:3]1

Participants

5

Procedure

A solution of ethyl (4-(2-keto-1-benzimidazolinyl)piperidin-1-yl)acetate (13.0 g, 42.8 mmol) in methanol (150 mL) was treated with an aqueous solution of sodium hydroxide (3 N, 30 mL, 90 mmol) and heated at reflux for 2 hours. The solution was cooled to room temperature and neutralized with the addition of concentrated hydrochloric acid (12 N, 7.5 mL). The solvent was evaporated in vacuo, and the resultant amorphous solid was dried in vacuo with heating (˜50° C.) overnight to give (4-(2-keto-1-benzimidazolinyl)piperidin-1-yl)acetic acid (17.2 g) which was used in the subsequent step without purification. MS m/z 304 (MH+); NMR(DMSO-d6): δ 1.74 (br d, 2 H), 2.53-2.67 (m, 2 H), 2.74-2.86 (m, 2 H), 3.33 (s, 2 H), 4.29-4.42 (m, 1 H), 6.97-7.05 (m, 3 H) and 7.38-7.43 (m, 1 H).

Workup

  1. temperatureheated
  2. temperatureat reflux for 2 hours
  3. customThe solvent was evaporated in vacuo
  4. customwas dried in vacuo
  5. temperaturewith heating (˜50° C.) overnight

Sources & evidence

ORD record
ord-b028b8350e4d4411abb02f9a1b95112d
Source dataset
uspto-grants-2005_01
Patent number
US06841552B1

Reaction notes

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