Lithium Hydroxide → 1-(2-azidoethyl)-1H-benzimidazole-5-carboxylic acid

HRID 555293Notes

Reaction equation

HRID 555293 reaction equation
C[O:2][C:3]([C:5]1[CH:18]=[CH:17][C:8]2[N:9]([CH2:12][CH2:13][N:14]=[N+:15]=[N-:16])[CH:10]=[N:11][C:7]=2[CH:6]=1)=[O:4].[Li+].[OH-]>C1COCC1.O>[N:14]([CH2:13][CH2:12][N:9]1[C:8]2[CH:17]=[CH:18][C:5]([C:3]([OH:4])=[O:2])=[CH:6][C:7]=2[N:11]=[CH:10]1)=[N+:15]=[N-:16]

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 866300571-(2-azidoethyl)-1H-benzimidazole-5-carboxylic acid methyl ester

Product 1

HCID 866300581-(2-azidoethyl)-1H-benzimidazole-5-carboxylic acidYield 89%

Reagents, catalysts & solvents 1

HCID 21881883Oxolane--water (1/1)Solvent

Procedure

To a solution of 1-(2-azidoethyl)-1H-benzimidazole-5-carboxylic acid methyl ester (5.0 g, 0.0204 mol) in THF/water 1:1 (100 mL) was added with stirring LiOH (0.73 g, 0.0306 mol) and the mixture was stirred for 5 h at ambient temperature. The solvent was evaporated and to the residue was added ice water (100 mL). The pH of the reaction mixture was adjusted to 5 with 1N HCl and the mixture extracted with EtOAc (5×100 mL). The combined organic phases were washed with saturated brine solution (100 mL), dried (Na2SO4) and the solvent evaporated affording 4.2 g (89%) of 1-(2-azidoethyl)-1H-benzimidazole-5-carboxylic acid as an ash coloured solid. MS-ESI m/z 232 (M+1); 1H NMR (300 MHz, DMSO-d6) δ 3.8 (t, 2H), 4.5 (t, 2H), 7.8 (d, 1H), 7.9 (d, 1H), 8.25 (s, 1H), 8.4 (s, 1H).

Workup

  1. customThe solvent was evaporated and to the residue
  2. additionwas added ice water (100 mL)
  3. extractionthe mixture extracted with EtOAc (5×100 mL)
  4. washThe combined organic phases were washed with saturated brine solution (100 mL)
  5. dry with materialdried (Na2SO4)
  6. customthe solvent evaporated

Sources & evidence

ORD record
ord-54576cc311a846e895ac86491f8983bc
Source dataset
uspto-grants-2011_11
Patent number
US08053431B2

Reaction notes

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