Реакция #52996

Уравнение реакции

oxalyl chloride

2-chloro-4-(1-pyrrolyl)benzoic acid methyl ester

→

2-chloro-4-(2-formyl-1-pyrrolyl)benzoic acid methyl ester

Растворители

CH2Cl2

DMF

CH2Cl2

DMF

Условия реакции

Обработка

1. 1
   workup.STIRRINGThe mixture was stirred at that temperature for 3 h
2. 2
   workup.STIRRINGThe mixture was stirred overnight
3. 3
   Другоеevaporated
4. 4
   ДругоеThe residue was partitioned between EtOAc and 0.2 M NaOAc
5. 5
   ДругоеThe EtOAc layer was separated
6. 6
   Экстракцияthe aqueous solution was extracted with EtOAc
7. 7
   ПромывкаThe combined EtOAc layer was washed with brine
8. 8
   Сушкаdried (MgSO4)
9. 9
   Фильтрацияfiltered
10. 10
    Другоеevaporated
11. 11
    ДругоеThe residue was purified by column chromatography (silica gel; eluent: hexane/EtOAc 3/1)

Методика

A solution of DMF (0.1 mL) in CH2Cl2 (2 mL) was added dropwise with stirring to a solution of oxalyl chloride (0.2 mL) in CH2Cl2 (16 mL) at −30° C. under N2. The mixture was stirred for 15 min and a solution of 2-chloro-4-(1-pyrrolyl)benzoic acid methyl ester (0.5 g) in DMF (4 mL) was added. The mixture was stirred at that temperature for 3 h and allowed to warm to room temperature. The mixture was stirred overnight and evaporated. The residue was partitioned between EtOAc and 0.2 M NaOAc. The EtOAc layer was separated and the aqueous solution was extracted with EtOAc. The combined EtOAc layer was washed with brine, dried (MgSO4), filtered and evaporated. The residue was purified by column chromatography (silica gel; eluent: hexane/EtOAc 3/1) to yield 2-chloro-4-(2-formyl-1-pyrrolyl)benzoic acid methyl ester (0.41 g). ESMS: 264 (MH+).

Источник