반응 #446031

반응 방정식

potassium tert.-butoxide

2-(5-isopropyl-5-methyl-4-oxoimidazolin-2-yl)-5-ethylpyridine-3-carboxylic acid

potassium tert.-butoxide

6-methoxymethyl-5-methylpyridine-2,3-dicarboxylic acid diethyl ester

2-amino-2,3-dimethylbutyramide

potassium

→

6-methoxy-5-methyl-2-(5-isopropyl-5-methyl-4-oxoimidazolin-2-yl)-pyridine-3-carboxylic acid

용매

toluene

반응 조건

후처리

1. 1
   workup.STIRRINGthe resulting red solution is stirred for 2 hours at 80° C.
2. 2
   여과filtered with suction
3. 3
   기타the crystals are dried
4. 4
   workup.DISSOLUTIONdissolved in 50 ml of saturated sodium chloride solution
5. 5
   추출extracted three times with 100 ml of ethyl acetate each time
6. 6
   건조The organic phase is dried over magnesium sulphate
7. 7
   여과filtered off with suction
8. 8
   농축concentrated by evaporation
9. 9
   기타The residue crystallises from ether/hexane 1:2 yielding 2.8 g of the above acid, which

실험 절차

5 g of potassium tert.-butoxide are added in portions at a temperature of 80° C. to a solution of 5.7 g of 6-methoxymethyl-5-methylpyridine-2,3-dicarboxylic acid diethyl ester and 2.6 g of 2-amino-2,3-dimethylbutyramide in 200 ml of dry toluene while stirring. Once the addition of the potassium tert.-butoxide is complete, the resulting red solution is stirred for 2 hours at 80° C., the potassium salt of 2-(5-isopropyl-5-methyl-4-oxoimidazolin-2-yl)-5-ethylpyridine-3-carboxylic acid being deposited in the form of a thick crystalline slurry. The mixture is cooled to room temperature and filtered with suction, and the crystals are dried and then dissolved in 50 ml of saturated sodium chloride solution. The solution is adjusted to pH 4 with concentrated hydrochloric acid and then extracted three times with 100 ml of ethyl acetate each time. The organic phase is dried over magnesium sulphate, filtered off with suction and concentrated by evaporation. The residue crystallises from ether/hexane 1:2 yielding 2.8 g of the above acid, which has a melting point of 151°-153° C.

출처