Nitric Acid → 2,2,2-Trichloro-1-(1-methyl-4-nitro-1H-pyrrol-2-yl)ethan-1-one

HRID 1841691Notes

Reaction equation

HRID 1841691 reaction equation
[Cl:1][C:2]([Cl:11])([Cl:10])[C:3]([C:5]1[NH:6][CH:7]=[CH:8][CH:9]=1)=[O:4].[N+:12]([O-:15])(O)=[O:13].[CH:16](O)(C)C>C(OC(=O)C)(=O)C>[N+:12]([C:8]1[CH:9]=[C:5]([C:3](=[O:4])[C:2]([Cl:1])([Cl:10])[Cl:11])[N:6]([CH3:16])[CH:7]=1)([O-:15])=[O:13]

Participants

5

Reactant 3

HCID 944Nitric AcidHCID 3776IsopropanolHCID 3214872-(Trichloroacetyl)pyrrole

Product 1

HCID 27599662,2,2-Trichloro-1-(1-methyl-4-nitro-1H-pyrrol-2-yl)ethan-1-oneYield 54%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Conditions

Temperature
-40 °C

Procedure

To a well stirred solution of trichloroacetylchloride (1 kg, 5.5 mole) in 1.5 liters of ethyl ether was added dropwise over a period of 3 hours a solution of N-methylpyrrole (14) (0.45 kg, 5.5 mole) in 1.5 liters of anhydrous ethyl ether. The reaction was allowed to stir for an additional 3 hours and quenched by the dropwise addition of a solution of 400 g of potassium carbonate in 1.5 liters of water. The layers were separated and the ether layer was concentrated in vacuo to provide 2-trichloroacetyl pyrrole (1.2 kg, 5.1 mole) as a yellow crystalline solid, which can be purified by recrystallization from benzene, but is sufficiently pure to be used without further purification. To a cooled (−40° C.) solution of 2-trichloroacetyl pyrrole (1.2 kg, 5.1 mole) in acetic anhydride (6 liters) flask equipped with a mechanical stirrer was added 440 ml of fuming nitric acid over a period of 1 hour while maintaining a temperature of −40° C. The reaction was carefully allowed to warm to room temperature and stirred an additional 4 hours after which the mixture was cooled to −30° C. and isopropyl alcohol (6 liters) was added. The solution was stirred at −20° C. for 30 minutes during which time a white precipitate formed. The solution was allowed to stand for 15 minutes and the resulting precipitate collected by vacuum filtration to provide (15) (0.8 kg, 54% yield). TLC (7:2 benzene/ethyl acetate) Rf 0.7; 1H NMR (DMSO-d6) δ 8.55 (d, 1H, J=1.7 Hz), 7.77 (d, 1H, J=1.7 Hz), 3.98 (s, 3H); 13C NMR (DMSO-d6) δ 173.3, 134.7, 133.2, 121.1, 116.9, 95.0, 51.5; IR (KBr) 1694, 1516, 1423, 1314, 1183, 1113, 998, 750; FABMS m/e 269.936 (M−H 269.9937 calc. for C7H5N2O3Cl3).

Workup

  1. customcan be purified by recrystallization from benzene
  2. customto be used without further purification
  3. customequipped with a mechanical stirrer
  4. temperatureto warm to room temperature
  5. temperaturewas cooled to −30° C.
  6. stirringThe solution was stirred at −20° C. for 30 minutes during which time a white precipitate
  7. customformed
  8. waitto stand for 15 minutes
  9. filtrationthe resulting precipitate collected by vacuum filtration

Sources & evidence

ORD record
ord-5599c66e1af848b6bd1603eb0c88459b
Source dataset
uspto-grants-2004_01
Patent number
US06683189B1

Reaction notes

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