Hydrochloric Acid → Clopyralid

HRID 371622Notes

Reaction equation

HRID 371622 reaction equation
[Cl:1][C:2]1[C:3]([C:12]([OH:14])=[O:13])=[N:4][C:5]([Cl:11])=[C:6](Cl)[C:7]=1NN.[OH-].[Na+].C(Cl)Cl.Cl>O>[Cl:1][C:2]1[C:3]([C:12]([OH:14])=[O:13])=[N:4][C:5]([Cl:11])=[CH:6][CH:7]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6344DichloromethaneHCID 14798Sodium Hydroxide2×HCID 13834393,5,6-Trichloro-4-hydrazinylpyridine-2-carboxylic acid

Product 1

HCID 15553ClopyralidYield 62%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent3×

Procedure

To a reaction flask containing 400 milliliters of water was added 30 grams (0.11 mole) of 3,5,6-trichloro-4-hydrazinopicolinic acid and 4.5 grams (0.11 mole) of sodium hydroxide dissolved in 25 milliliters of water. The reaction was heated to reflux and maintained under reflux while an additional 4.5 grams of sodium hydroxide dissolved in 25 milliliters of water was added dropwise over 50 minutes. The resulting solution was thereafter heated an additional 45 minutes under reflux and cooled to room temperature. The reaction mixture was mixed with 100 milliliters of methylene chloride and the solution acidified with 35 milliliters of concentrated hydrochloric acid. The two phases which formed were separated and the aqueous layer extracted twice with methylene chloride. The extracts were combined and dried over magnesium sulfate and the solvent evaporated to give 13.1 grams (62 percent of theoretical) of 3,6-dichloropicolinic acid.

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux
  3. temperaturemaintained
  4. additionwas added dropwise over 50 minutes
  5. temperatureThe resulting solution was thereafter heated an additional 45 minutes
  6. temperatureunder reflux
  7. customThe two phases which formed
  8. customwere separated
  9. extractionthe aqueous layer extracted twice with methylene chloride
  10. dry with materialdried over magnesium sulfate
  11. customthe solvent evaporated

Sources & evidence

ORD record
ord-2cc8b7db2aa94e2487cb2d46a50d116f
Source dataset
uspto-grants-1978_05
Patent number
US04087431

Reaction notes

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