2,2-Diethoxyethylamine → 2,2-Dimethoxy-n-[(1-methyl-1h-benzimidazol-2-yl)methyl]ethanamine

HRID 1174216Notes

Reaction equation

HRID 1174216 reaction equation
[CH3:1][N:2]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[N:4]=[C:3]1[CH:11]=O.[CH2:13]([O:15][CH:16]([O:19][CH2:20]C)[CH2:17][NH2:18])C.[BH3-]C#N.[Na+]>CO.C(O)(=O)C>[CH3:13][O:15][CH:16]([O:19][CH3:20])[CH2:17][NH:18][CH2:11][C:3]1[N:2]([CH3:1])[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[N:4]=1

Participants

6

Reactant 3

HCID 695242,2-DiethoxyethylamineHCID 7620841-methyl-1H-1,3-benzodiazole-2-carbaldehydeHCID 5003444Sodium cyanoborohydride

Product 1

HCID 552185252,2-Dimethoxy-n-[(1-methyl-1h-benzimidazol-2-yl)methyl]ethanamineYield 77.1%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 887MethanolSolvent

Procedure

A solution of 1-methyl-2-formylbenzimidazole (1 g) in methanol (27 mL) and acetic acid (0.54 mL) was treated with aminoacetaldehyde diethylacetal (0.9 g, 1 eq.) and NaCNBH3 (0.85 g, 2 eq.) at 25° C., stirred for 1 hour. The mixture was partitioned between water and ethyl acetate. The organic phase layer was separated, washed sequentially with saturated NaHCO3 and brine, and concentrated. The residue was chromatographed on silica gel, eluting with 8% methanol/dichloromethane to give the title compound (1.2 g 64% yield).

Workup

  1. customThe mixture was partitioned between water and ethyl acetate
  2. customThe organic phase layer was separated
  3. washwashed sequentially with saturated NaHCO3 and brine
  4. concentrationconcentrated
  5. customThe residue was chromatographed on silica gel
  6. washeluting with 8% methanol/dichloromethane

Sources & evidence

ORD record
ord-e5daae675dfb421997044dbe4d66607e
Source dataset
uspto-grants-2010_11
Patent number
US07834043B2

Reaction notes

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