Nitric Acid → 3-Methoxy-5-nitropyridin-2-ol

Sodium hydroxide (8.6 g, 0.215 mole) and 2,3-dihydroxypyridine (22.0 g, 0.20 mole) were added to distilled water (75 ml). After cooling to 5° C., dimethylsulfate (25.0 g, 0.21 mole) was added dropwise; the reaction mixture was stirred for 20 hours while slowly warming to room temperature. The water was removed in vacuo (approximately 65° C.) to obtain a syrup which was dissolved in concentrated sulfuric acid (50 to 60 ml) at 5° C. A cold mixture of concentrated nitric acid (20 ml) in concentrated sulfuric acid (20 ml) was added at a rate to maintain the reaction mixture between 10° to 15° C. After the addition was complete, the mixture was stirred for 30 minutes at 5° C. and then poured onto ice (approximately 400 ml). The resulting red precipitate was collected by filtration and recrystallized from water; yield, 5.8 g (17 percent).

1. distillationto distilled water (75 ml)
2. temperaturewhile slowly warming to room temperature
3. customThe water was removed in vacuo (approximately 65° C.)
4. customto obtain a syrup which
5. additionwas added at a rate
6. temperatureto maintain the reaction mixture between 10° to 15° C
7. additionAfter the addition
8. stirringthe mixture was stirred for 30 minutes at 5° C.
9. additionpoured onto ice (approximately 400 ml)
10. filtrationThe resulting red precipitate was collected by filtration
11. customrecrystallized from water
12. customyield

ORD 기록

ord-4aba1ba0e3934f5f9504ca9a36dedcd5

출처 데이터셋

uspto-grants-1981_06

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US04273706