Реакция #90301

Уравнение реакции

(Z)-2,5-dichloro-N′-hydroxy-4,6-dimethylnicotinimidamide

pyridine

4-hydroxy-3-methoxy-5-nitrobenzoic acid

HCl

→

4-(3-(2,5-dichloro-4,6-dimethylpyridin-3-yl)-1,2,4-oxadiazol-5-yl)-2-methoxy-6-nitrophenol

Выход 62.7%

Растворители

thionyl chloride

Условия реакции

Обработка

1. 1
   ДругоеThe excess of thionyl chloride was removed under vacuum
2. 2
   workup.DISSOLUTIONThe resulting yellow solid was dissolved in DMA (15.4 mL)
3. 3
   ТемператураThe red solution was heated to 120° C. for 2.5 hours
4. 4
   ТемператураThe reaction mixture was cooled to room temperature
5. 5
   ФильтрацияThe yellow precipitate was filtered off
6. 6
   Промывкаwashed with water
7. 7
   Другоеdried under vacuum
8. 8
   ДругоеRecrystallization from dichloromethane-isopropanol mixture

Методика

A stirred suspension of 4-hydroxy-3-methoxy-5-nitrobenzoic acid (2.00 g, 9.38 mmol) in thionyl chloride (8.2 mL) was heated at 80° C. for two hours. The excess of thionyl chloride was removed under vacuum. The resulting yellow solid was dissolved in DMA (15.4 mL), then (Z)-2,5-dichloro-N′-hydroxy-4,6-dimethylnicotinimidamide (2.636 g, 11.26 mmol) and pyridine (6.2 mL) were added. The red solution was heated to 120° C. for 2.5 hours. The reaction mixture was cooled to room temperature and poured into a mixture of cc HCl (10 ml) and ice (80 g), then stirred for thirty minutes. The yellow precipitate was filtered off, washed with water and dried under vacuum. Recrystallization from dichloromethane-isopropanol mixture afforded 2.42 g (62%) of 4-(3-(2,5-dichloro-4,6-dimethylpyridin-3-yl)-1,2,4-oxadiazol-5-yl)-2-methoxy-6-nitrophenol as yellow crystalline.

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