Phosphorus oxybromide → 3-Pyridinecarboxylic acid, 2-bromo-6-(trifluoromethyl)-, methyl ester

HRID 275254Notes

Reaction equation

HRID 275254 reaction equation
O=[C:2]1[C:7]([C:8]([O:10][CH3:11])=[O:9])=[CH:6][CH:5]=[C:4]([C:12]([F:15])([F:14])[F:13])[NH:3]1.P(Br)(Br)([Br:18])=O>O>[Br:18][C:2]1[C:7]([C:8]([O:10][CH3:11])=[O:9])=[CH:6][CH:5]=[C:4]([C:12]([F:15])([F:14])[F:13])[N:3]=1

Participants

4

Reactant 2

HCID 24613Phosphorus oxybromideHCID 15217844Methyl 2-oxo-6-(trifluoromethyl)-1,2-dihydropyridine-3-carboxylate

Product 1

HCID 152178453-Pyridinecarboxylic acid, 2-bromo-6-(trifluoromethyl)-, methyl esterYield 13.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A suspension of 22.0 g (0.100 mol) of the product from Example 1 and 28.7 g (0.100 mol) of phosphorous oxybromide was heated at 75°-120° C. over 45 minutes utilizing an oil bath as the heat source. The reaction was also connected to a water scrubber to trap the gas by-products. The mixture was then cooled to room temperature, diluted with water and extracted with methylene chloride. The combined organic layers were washed with saturated sodium bicarbonate solution, washed with brine, dried over magnesium sulfate and evaporated to an oil which was purified by flesh chromatography utilizing 20% ethyl acetate/petroleum ether as the eluent to afford 3.8 g (13.3%) of an oil. 1H NMR (CDCl3) δ4.0 (3H, s), 7.72 (1H, d, J=8 Hz), 8.2 (1H, d, J=8 Hz); IR (neat) 1740, 1590, 1455, 1335, 1275, 1140, 1100, 1050 cm-1.

Workup

  1. temperaturewas heated at 75°-120° C. over 45 minutes
  2. extractionextracted with methylene chloride
  3. washThe combined organic layers were washed with saturated sodium bicarbonate solution
  4. washwashed with brine
  5. dry with materialdried over magnesium sulfate
  6. customevaporated to an oil which
  7. customwas purified by flesh chromatography

Sources & evidence

ORD record
ord-d8416baf97a54f5c9b1f95636e6816e0
Source dataset
uspto-grants-1995_02
Patent number
US05393734

Reaction notes

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