Nitric Acid → 1-Methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chloro-5-nitrophenyl)pyrazole

HRID 634562Notes

Reaction equation

HRID 634562 reaction equation
[CH3:1][N:2]1[C:6]([O:7][CH:8]([F:10])[F:9])=[C:5]([Cl:11])[C:4]([C:12]2[CH:17]=[CH:16][C:15]([Cl:18])=[CH:14][C:13]=2[F:19])=[N:3]1.N1C=CC=N1.[N+:25]([O-])([OH:27])=[O:26]>S(=O)(=O)(O)O>[CH3:1][N:2]1[C:6]([O:7][CH:8]([F:10])[F:9])=[C:5]([Cl:11])[C:4]([C:12]2[CH:17]=[C:16]([N+:25]([O-:27])=[O:26])[C:15]([Cl:18])=[CH:14][C:13]=2[F:19])=[N:3]1

Participants

5

Reactant 3

HCID 944Nitric AcidHCID 1048PyrazoleHCID 114383281-Methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chlorophenyl)pyrazole

Product 1

HCID 156723371-Methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chloro-5-nitrophenyl)pyrazoleYield 97.3%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

A mixture of 18.0 grams (0.058 mole) of 1-methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chlorophenyl)pyrazole and 120 mL of concentrated sulfuric acid was stirred, and when the pyrazole was dissolved, the solution was cooled to 0° C. To this was added dropwise 5.5 mL (0.074 mole) of 70% nitric acid at a rate to maintain the reaction mixture temperature below 3° C. Upon completion of addition the reaction mixture was allowed to warm to about 10° C. where it stirred for two hours. After this time the reaction mixture was poured into ice-water and then extracted with several portions of diethyl ether. The combined extracts were dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure, yielding 20.1 grams of 1-methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chloro-5-nitrophenyl)pyrazole. The NMR spectrum was consistent with the proposed structure.

Workup

  1. temperatureto maintain the reaction mixture temperature below 3° C
  2. additionUpon completion of addition the reaction mixture
  3. temperatureto warm to about 10° C. where it
  4. stirringstirred for two hours
  5. extractionextracted with several portions of diethyl ether
  6. dry with materialThe combined extracts were dried with magnesium sulfate
  7. filtrationfiltered
  8. concentrationThe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-87d97ec8f59f4ae7a27e0969e6e8f9b5
Source dataset
uspto-grants-2001_02
Patent number
USH0001942H1

Reaction notes

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