Boron trifluoride etherate → 2,3-Dichloro-5-fluoropyridine

HRID 1368178Notes

Reaction equation

HRID 1368178 reaction equation
N[C:2]1[CH:3]=[C:4]([Cl:9])[C:5]([Cl:8])=[N:6][CH:7]=1.B(F)(F)[F:11].CCOCC.C(ON=O)(C)(C)C.CCCCCC>ClCCl>[Cl:8][C:5]1[C:4]([Cl:9])=[CH:3][C:2]([F:11])=[CH:7][N:6]=1

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 8058HexaneHCID 10906Tert-Butyl nitriteHCID 145952195-Amino-2,3-dichloropyridine

Product 1

HCID 185200082,3-Dichloro-5-fluoropyridine

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Conditions

Temperature
-5 °C

Procedure

5-Amino-2,3-dichloropyridine (0.80 g) in dichloromethane (10 ml) was added to boron trifluoride etherate (0.92 ml) at −15° C. under nitrogen. Dichloromethane (5 ml) was added followed by t-butylnitrite (0.71 ml) in dichloromethane (5 ml). After 15 minutes the mixture was allowed to warm to −5° C. over 20 minutes. Hexane was added and the resulting solid was filtered, air-dried and washed with ether and stored at approximately −20° C. overnight. The solid was then heated until gas evolution had ceased and the product kugelrohr distilled to give 2,3-dichloro-5-fluoropyridine (0.104 g).

Workup

  1. filtrationthe resulting solid was filtered
  2. customair-dried
  3. washwashed with ether
  4. waitstored at approximately −20° C. overnight
  5. temperatureThe solid was then heated until gas evolution
  6. distillationthe product kugelrohr distilled

Sources & evidence

ORD record
ord-daba40b71b4a49d495f2c8884d15d7a7
Source dataset
uspto-grants-2003_06
Patent number
US06573275B1

Reaction notes

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