تفاعل #2467967

معادلة التفاعل

Methyl 4-hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate

sulfuric acid

nitric acid

→

semi-solid

المردود 20.0%

Methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate

المردود 20.0%

المذيبات

water

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONThe mixture was poured into ice
2. 2
   استخلاصextracted with ethyl acetate (3×100 mL)
3. 3
   غسيلThe combined organic layer was washed with water, brine
4. 4
   تجفيفdried over sodium sulfate
5. 5
   ترشيحThe solution was filtered
6. 6
   أخرىevaporated the solvent
7. 7
   أخرىThe residue was chromatographed over silica gel column

الإجراء التجريبي

Methyl 4-hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate (5 g, 23.14 mmol) was added slowly for 15 min at 0 to −5° C. to concentrated sulfuric acid (25 mL). Then concentrated nitric acid (3.2 mL, 70%, 34.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h. The mixture was poured into ice cooled water and extracted with ethyl acetate (3×100 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using chloroform-methanol (95:5) as eluents to give the product as a yellow color semi-solid (1.2 g, 20%).

المصدر