Carbon Dioxide → 2,6-Dichloronicotinic acid

HRID 917615Notes

Reaction equation

HRID 917615 reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[Cl:13][C:14]1[CH:19]=[CH:18][CH:17]=[C:16]([Cl:20])[N:15]=1.[C:21](=[O:23])=[O:22]>O1CCCC1>[Cl:20][C:16]1[N:15]=[C:14]([Cl:13])[CH:19]=[CH:18][C:17]=1[C:21]([OH:23])=[O:22]

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 7912DiisopropylamineHCID 169892,6-DichloropyridineHCID 178418339Butyllithium

Product 1

HCID 8540472,6-Dichloronicotinic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

To a solution of diisopropylamine 3.76 g in tetrahydrofuran 25 ml is dropped at −78° C. n-butyllithium (23.2 ml). The mixture is stirred at 0° C. for 10 minutes and thereto is added 2,6-dichloropyridine 5.0 g in tetrahydrofuran 25 ml at −78° C. over a period of 20 minutes. The mixture is stirred at −78° C. for 3 hours. The reaction mixture is poured into powdered dry ice and is left at room temperature overnight. After removal of the solvent the residue is dissolved in a mixture of ethyl acetate and a 10% aqueous sodium hydroxide solution, and the water layer is separated and made acid with concentrated hydrochloric acid. The resulting colorless precipitate is filtered and washed with cold water to give 2,6-dichloronicotinic acid 4.50 g. mp 148-150° C., MS(ESI): 190(M−H)−

Workup

  1. stirringThe mixture is stirred at −78° C. for 3 hours
  2. waitis left at room temperature overnight
  3. customAfter removal of the solvent the residue
  4. dissolutionis dissolved in a mixture of ethyl acetate
  5. customa 10% aqueous sodium hydroxide solution, and the water layer is separated
  6. filtrationThe resulting colorless precipitate is filtered
  7. washwashed with cold water

Sources & evidence

ORD record
ord-238904cc2628427998604d1044dc86f5
Source dataset
uspto-grants-2007_09
Patent number
US07273868B2

Reaction notes

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