Nitric Acid → 1,3-dimethyl-4-nitro-1H-pyrazole-5-carboxylic acid

HRID 72183

Reaction equation

HRID 72183 reaction equation
[N+:1]([O-:4])(O)=[O:2].S(=O)(=O)(O)O.[CH3:10][N:11]1[C:15]([C:16]([OH:18])=[O:17])=[CH:14][C:13]([CH3:19])=[N:12]1>>[CH3:10][N:11]1[C:15]([C:16]([OH:18])=[O:17])=[C:14]([N+:1]([O-:4])=[O:2])[C:13]([CH3:19])=[N:12]1

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 5877211,3-Dimethyl-1H-pyrazole-5-carboxylic acid

Product 1

HCID 12297711,3-dimethyl-4-nitro-1H-pyrazole-5-carboxylic acidYield 96.3%

Conditions

Temperature
60 °C

Procedure

To fuming nitric acid (1.26 mL, 29.97 mmol, 2.0 eq.) at 0° C. was slowly added fuming sulfuric acid (9.76 mL, 104.90 mmol, 7.0 eq.) dropwise over 30 minutes. 1,3-Dimethyl-1H-pyrazole-5-carboxylic acid (2.10 g, 14.98 mmol) was then added portion wise, maintaining the internal temperature below 60° C. The reaction mixture was stirred at 60° C. under N2 for 4 h and then cooled to room temperature (RT). The reaction mixture was poured onto ice. Once ice melted the reaction mixture was extracted with EtOAc (3×500 mL). The organic layers were combined and washed with water and brine, dried (Na2SO4), filtered and evaporated in vacuo to give the desired compound as a white solid (2.67 g, 96.1%). 1H NMR (DMSO-d6, 500 MHz) δ ppm 3.87 (s, 3H), 2.39 (s, 3H); TLC (15% MeOH/DCM): Rf=0.12.

Workup

  1. customat 0° C.
  2. customdropwise over 30 minutes
  3. temperaturemaintaining the internal temperature below 60° C
  4. temperaturecooled to room temperature (RT)
  5. additionThe reaction mixture was poured onto ice
  6. extractionwas extracted with EtOAc (3×500 mL)
  7. washwashed with water and brine
  8. dry with materialdried (Na2SO4)
  9. filtrationfiltered
  10. customevaporated in vacuo

Sources & evidence

ORD record
ord-a68f2726edf84922b23b03bd1386728a
Source dataset
uspto-grants-2014_09
Patent number
US08828990B2

Linked notes

Loading…