تفاعل #68827

معادلة التفاعل

sulfuric acid

4-[5-(1,4-dioxa-8-aza-spiro[4.5]dec-8-yl)-pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid

intermediate 7.1

4-[5-(1,4-dioxa-8-aza-spiro[4.5]dec-8-yl)-pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid

sodium hydroxide

→

6′-(3,4-dihydro-2H-quinoxalin-1-yl)-2,3,5,6-tetrahydro-[1,3′]bipyridinyl-4-one

المذيبات

water

acetone

water

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةIt is cooled on an ice bath
2. 2
   استخلاصis extracted twice with ethyl acetate
3. 3
   غسيلThe combined organic phases are washed with water
4. 4
   تجفيفdried over sodium sulfate
5. 5
   ترشيحfiltered
6. 6
   أخرىevaporated to dryness
7. 7
   أخرىThe raw product obtained
8. 8
   أخرىis chromatographed on silica gel
9. 9
   غسيلeluting with a gradient of ternary solvents, on the one hand heptane and on the other hand heptane/ethyl acetate/methanol 4/5/1 varying from 10% to 100%

الإجراء التجريبي

In a 150-ml flask, 5.51 g of tert-butyl ester of 4-[5-(1,4-dioxa-8-aza-spiro[4.5]dec-8-yl)-pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid (intermediate 7.1) is put in 21 ml of tetrahydrofuran, 21 ml of water and 20 ml of acetone. It is cooled on an ice bath and 8.24 ml of 95% sulfuric acid is added gently. It is stirred at room temperature for 18 h. The solution is then poured into water. 5N sodium hydroxide is added to basic pH and it is extracted twice with ethyl acetate. The combined organic phases are washed with water, dried over sodium sulfate, filtered and evaporated to dryness. The raw product obtained is chromatographed on silica gel, eluting with a gradient of ternary solvents, on the one hand heptane and on the other hand heptane/ethyl acetate/methanol 4/5/1 varying from 10% to 100%. 2.39 g of 6′-(3,4-dihydro-2H-quinoxalin-1-yl)-2,3,5,6-tetrahydro-[1,3′]bipyridinyl-4-one is obtained.

المصدر