Reaction #1726732

Reaction equation

2,4,6-trimethylbenzenesulfonyl chloride

triethylamine

2,4,6-trimethylbenzenesulfonyl chloride

2,4,6-trimethylbenzenesulfonyl chloride

triethylamine

1-(5-hydroxy-1H-benzimidazol-2-yl)-3-(2-methoxyethyl)urea

→

resin

Yield 38.8%

2-{[(2-Methoxyethyl)carbamoyl]amino}-1H-benzimidazol-5-yl 2,4,6-trimethylbenzenesulfonate

Yield 38.8%

Solvents

acetone

Conditions

Workup

1. 1
   workup.ADDITIONare added
2. 2
   workup.ADDITIONare added
3. 3
   ConcentrationAfter concentrating to dryness under reduced pressure (13 kPa)
4. 4
   Extractionextracted with three times 40 cm3 of ethyl acetate
5. 5
   DryingThe organic phases are dried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated under reduced pressure

Procedure

To a suspension of 200 mg of 1-(5-hydroxy-1H-benzimidazol-2-yl)-3-(2-methoxyethyl)urea in 50 cm3 of acetone are added 0.162 cm3 of triethylamine and 192 mg of 2,4,6-trimethylbenzenesulfonyl chloride. After stirring for about 20 hours at a temperature in the region of 20° C., 95 mg of 2,4,6-trimethylbenzenesulfonyl chloride and 0.08 cm3 of triethylamine are added. After stirring for a further 3 hours at the same temperature, 95 mg of 2,4,6-trimethylbenzenesulfonyl chloride are added and the suspension is stirred for about 20 hours. After concentrating to dryness under reduced pressure (13 kPa), the residue is taken up in 50 cm3 of water and extracted with three times 40 cm3 of ethyl acetate. The organic phases are dried over magnesium sulfate, filtered and concentrated under reduced pressure. After flash chromatography on a column of silica [eluent: dichloromethane/methanol (95/5 by volume)], 134 mg of a resin are obtained, which resin is solidified in 7 cm3 of diisopropyl ether and 7 cm3 of diethyl ether. After filtration and drying under reduced pressure (13 kPa) over phosphorus pentoxide, 123 mg of 2-{[(2-methoxyethyl)carbamoyl]amino}-1H-benzimidazol-5-yl 2,4,6-trimethylbenzenesulfonate are obtained in the form of a solid, the characteristics of which are as follows:

Source