Reaction #52189

Reaction equation

O-(Benzotriazole-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate

2-[2-(4-Cyanophenyl)-ethyl]-1-methyl-benzimidazole-5-yl-carboxylic acid

4-(3-phenyl-allyl)-piperazine

triethylamine

→

2-[2-(4-Cyanophenyl)-ethyl]-1-methyl-benzimidazole-5-yl-carboxylic acid-[4-(3-phenyl-allyl)-piperazinyl]-amide

Solvents

ethyl acetate

dimethylformamide

Conditions

Workup

1. 1
   Washis washed with saturated, aqueous sodium bicarbonate solution
2. 2
   Dryingwith water, and dried over sodium sulphate
3. 3
   Otherthe product purified chromatographically (silica gel; gradient; acetic ester/methanol 100% in 60% acetic ester)

Procedure

0.4 g of 2-[2-(4-Cyanophenyl)-ethyl]-1-methyl-benzimidazole-5-yl-carboxylic acid (1.3 mmol), 4-(3-phenyl-allyl)-piperazine (0.26 g, 1.3 mmol) and 0.4 ml of triethylamine are dissolved in 8 ml of dimethylformamide. 0.54 g of O-(Benzotriazole-1-yl)-N,N,N′,N′-tetramethyluronium-tetrafluoroborate (═TBTU; 1.7 mmol) are added and stirred for 24 h at room temperature. After diluting with 20 ml of ethyl acetate, it is washed with saturated, aqueous sodium bicarbonate solution and with water, and dried over sodium sulphate. The solvent is boiled down and the product purified chromatographically (silica gel; gradient; acetic ester/methanol 100% in 60% acetic ester). Yield: 0.52 g (80%); yellow oil.

Source