Nitric Acid → 3-(3-chloro-4-nitro-1H-pyrazol-1-yl)pyridine

HRID 57092

Reaktionsgleichung

Reaktionsgleichung von HRID 57092
[Cl:1][C:2]1[CH:6]=[CH:5][N:4]([C:7]2[CH:8]=[N:9][CH:10]=[CH:11][CH:12]=2)[N:3]=1.S(=O)(=O)(O)O.[N+:18]([O-])([OH:20])=[O:19].S(=O)(=O)(O)O.[N+]([O-])(O)=O.[OH-].[Na+]>O>[Cl:1][C:2]1[C:6]([N+:18]([O-:20])=[O:19])=[CH:5][N:4]([C:7]2[CH:8]=[N:9][CH:10]=[CH:11][CH:12]=2)[N:3]=1

Komponenten

7

Reaktionsbedingungen

Temperatur
5 °C

Versuchsvorschrift

To a 100 mL round bottom flask was charged 3-(3-chloro-1H-pyrazol-1-yl)pyridine (2.0 g, 11 mmol) and concentrated sulfuric acid (4 mL). This suspension was cooled to ˜5° C. and 2:1 (v/v) concentrated nitric acid/sulfuric acid (3 mL, prepared by adding the concentrated sulfuric acid to a stirring and cooling solution of the nitric acid) was added dropwise at a rate such that the internal temperature was maintained <15° C. The reaction was allowed to warm to 20° C. and stirred for 18 hours. A sample of the reaction mixture was carefully diluted into water, basified with 50% sodium hydroxide (NaOH) and extracted with ethyl acetate. Analysis of the organic layer indicated that the reaction was complete. The reaction mixture was carefully added to ice cold water (100 mL) at <20° C. and basified with 50% sodium hydroxide at <20° C. The resulting light yellow suspension was stirred for 2 hours and filtered. The filter cake was rinsed with water (3×20 mL) and dried to afford an off-white solid (2.5 g, quantitative): mp 141-143° C.; 1H NMR (400 MHz, DMSO-d6) δ 9.86 (s, 1H), 9.23-9.06 (m, 1H), 8.75-8.60 (m, 1H), 8.33 (ddd, J=8.4, 2.8, 1.4 Hz, 1H), 7.64 (ddd, J=8.5, 4.7, 0.7 Hz, 1H); 13C NMR (101 MHz, DMSO-d6) δ 149.49, 140.75, 136.02, 134.43, 132.14, 131.76, 127.22, 124.31; EIMS m/z 224 ([M]+).

Aufarbeitung

  1. additionwas added dropwise at a rate such that the internal temperature
  2. temperaturewas maintained <15° C
  3. temperatureto warm to 20° C.
  4. extractionextracted with ethyl acetate
  5. additionThe reaction mixture was carefully added to ice cold water (100 mL) at <20° C. and basified with 50% sodium hydroxide at <20° C
  6. stirringThe resulting light yellow suspension was stirred for 2 hours
  7. filtrationfiltered
  8. washThe filter cake was rinsed with water (3×20 mL)
  9. customdried
  10. customto afford an off-white solid (2.5 g, quantitative)

Quellen und Nachweise

ORD-Eintrag
ord-fa9aa42b2639486b80cb3ef2c3a79e0b
Quelldatensatz
uspto-grants-2016_09
Patentnummer
US09434712B2

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