Nitric Acid → Methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate

HRID 378775Notes

Reaction equation

HRID 378775 reaction equation
[N+:1]([O-:4])(O)=[O:2].S(=O)(=O)(O)O.[Br:10][C:11]1[N:16]=[C:15]([C:17]([O:19][CH3:20])=[O:18])[C:14]([Cl:21])=[CH:13][CH:12]=1>>[Br:10][C:11]1[N:16]=[C:15]([C:17]([O:19][CH3:20])=[O:18])[C:14]([Cl:21])=[C:13]([N+:1]([O-:4])=[O:2])[CH:12]=1

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 21696654Methyl 6-bromo-3-chloropicolinate

Product 1

HCID 21696610Methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate

Conditions

Temperature
70 °C

Procedure

To a solution of fuming nitric acid (10 mL) and fuming sulfuric acid (10 mL) was added methyl 6-bromo-3-chloropyridine-2-carboxylate, N-oxide and the reaction was heated to 70° C. in an oil bath for 4 hr. The mixture was poured over ice water (100 mL) and extracted with ethyl acetate (3×75 mL) and the combined extracts were backwashed with brine, dried (Na2SO4) and concentrated. The dark oil was chromatographed over silica in 4:1 EtOAc/hexane to give methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate, N-oxide (0.007 mol, 2.2 g). 1H NMR (CDCl3): δ 4.1 (3H, s), 8.4 (1H, s).

Workup

  1. extractionextracted with ethyl acetate (3×75 mL)
  2. dry with materialdried (Na2SO4)
  3. concentrationconcentrated
  4. customThe dark oil was chromatographed over silica in 4:1 EtOAc/hexane

Sources & evidence

ORD record
ord-acf0f52ede6d4866ab564428aa773da1
Source dataset
uspto-grants-2001_10
Patent number
US06297197B1

Reaction notes

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