Reaktion #1119119

Reaktionsgleichung

3-hydroxypyrazine-2-carboxylic acid

phosphorus oxychloride

4-amino-1,1,3-trimethylindane

triethylamine

→

light yellow crystals

Ausbeute 61.0%

3-chloro-N-(1,1,3-trimethylindan-4-yl)pyrazine-2-carboxamide

Ausbeute 61.0%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas refluxed for 3 hours
2. 2
   SonstigeThe resultant reaction solution
3. 3
   workup.DISTILLATIONwas distilled
4. 4
   Sonstigeto remove excess phosphorus oxychloride
5. 5
   workup.ADDITIONTo the residue 5 ml of ethyl acetate was added
6. 6
   Waschensequentially washed with water, sodium hydrogen carbonate, water
7. 7
   TrocknenThe washed solution was dried with magnesium sulfate
8. 8
   Einengenconcentrated under reduced pressure
9. 9
   SonstigeThe concentrated residue was separated
10. 10
    Sonstigepurified by silica gel column chromatography (eluent: ethyl acetate/n-hexane =1/4)

Vorschrift

A mixture of 0.5 g (3.57 mmols) of 3-hydroxypyrazine-2-carboxylic acid, 3 ml of phosphorus oxychloride, and one drop of pyridine was refluxed for 3 hours. The resultant reaction solution was distilled to remove excess phosphorus oxychloride. To the residue 5 ml of ethyl acetate was added. The solution was added dropwise to 10 ml of an ethyl acetate solution of 0.53 g (3 mmols) of 4-amino-1,1,3-trimethylindane and 0.4 g (3.96 mmols) of triethylamine. The resultant mixture was stirred at room temperature for 2 hours and then sequentially washed with water, sodium hydrogen carbonate, water, and a saturated brine. The washed solution was dried with magnesium sulfate and then concentrated under reduced pressure. The concentrated residue was separated and purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane =1/4), to obtain 0.58 g of light yellow crystals (Compound No. 10 shown in Table 5). The yield was 61%.

Quelle