Reaction #1869174

Reaction equation

NaHCO3

2-{1-[(6-chloroimidazo[2,1-b][1,3]thiazol-5-yl)sulfonyl]-1H-indol-3-yl}ethylamine hydrochloride

triethylamine

acetic anhydride

→

title product

Yield 92.0%

N-(2-{1-[(6-Chloro-imidazo[2,1-b][1,3]thiazol-5-yl)sulfonyl]-1H-indol-3-yl}-ethyl)acetamide

Yield 92.0%

Solvents

dichloromethane

Conditions

Workup

1. 1
   Extractionextracted with dichloromethane
2. 2
   Dryingdried over MgSO4
3. 3
   Concentrationconcentrated in vacuo to a foam
4. 4
   workup.ADDITIONThe foam is treated with 20:80 ethyl acetate
5. 5
   Concentrationhexane and concentrated in vacuo to a solid
6. 6
   OtherThis is triturated with ether
7. 7
   Filtrationfiltered
8. 8
   OtherThe filtercake is dried

Procedure

A stirred mixture of 2-{1-[(6-chloroimidazo[2,1-b][1,3]thiazol-5-yl)sulfonyl]-1H-indol-3-yl}ethylamine hydrochloride, 417 mg, 1.00 mmol) in dichloromethane and triethylamine (0.40 mL, 3.0 mmol) is treated with catalytic 4-dimethylaminopyridine (DMAP) (˜5 mg) at room temperature under nitrogen. The heterogeneous mixture is treated with acetic anhydride (0.30 mL, 3.2 mmol) and the reaction becomes homogeneous. After 16 h, the reaction is treated with saturated aqueous NaHCO3 (8 mL) for 0.3 h and then extracted with dichloromethane. The extracts are combined, dried over MgSO4 and concentrated in vacuo to a foam. The foam is treated with 20:80 ethyl acetate:hexane and concentrated in vacuo to a solid. This is triturated with ether and filtered. The filtercake is dried to afford the title product as a white solid, 389 mg (92% yield), mp 150-152° C., characterized by CHN elemental analysis and 1H NMR.

Source