Reaction #446032

Reaction equation

potassium tert.-butoxide

6-(thiophen-3-yl)-pyridine-2,3-dicarboxylic acid diethyl ester

2-amino-2,3-dimethyl- butyramide

→

6-(thiophen-3-yl)-2-(5-isopropyl-5-methyl-4-oxo-imidazol-2-yl)-pyridine-3-carboxylic acid

Yield 85.7%

Solvents

toluene

Conditions

Workup

1. 1
   workup.ADDITIONThe reaction solution is then poured onto ice
2. 2
   Otherthe phases are separated
3. 3
   OtherAfter some time the above acid crystallises out and
4. 4
   Filtrationis filtered off with suction
5. 5
   Otherdried

Procedure

12 g of potassium tert.-butoxide are added to a solution of 14 g of 6-(thiophen-3-yl)-pyridine-2,3-dicarboxylic acid diethyl ester and 6 g of 2-amino-2,3-dimethyl- butyramide in 100 ml of dry toluene while stirring and the solution is heated at 80° C. for 5 hours. The reaction solution is then poured onto ice, the phases are separated and the aqueous phase is acidified with 10 ml of glacial acetic acid. After some time the above acid crystallises out and is filtered off with suction and dried. In this manner 13.5 g of 6-(thiophen-3-yl)-2-(5-isopropyl-5-methyl-4-oxo-imidazol-2-yl)-pyridine-3-carboxylic acid having a melting point of 253°-257° C. are obtained.

Source