반응 #159366

반응 방정식

ammonium hydroxide

1,3-dimethyl-4-nitro-1H-pyrazole-5-carboxylic acid

oxalyl chloride

→

desired product

수율 51.5%

1,3-dimethyl-4-nitro-1H-pyrazole-5-carboxamide

수율 51.5%

용매

dichloromethane

DMF

반응 조건

후처리

1. 1
   기타Volatile solvent was evaporated in vacuo
2. 2
   workup.DISSOLUTIONthe crude material dissolved in anhydrous THF (20 mL)
3. 3
   workup.STIRRINGthe reaction mixture was stirred at RT for 16 hours
4. 4
   농축The reaction mixture was concentrated in vacuo
5. 5
   workup.ADDITIONthe residue was diluted with ethyl acetate
6. 6
   세척The organic layer was washed with saturated aqueous solution of sodium bicarbonate, water and brine
7. 7
   건조dried (Na2SO4)
8. 8
   여과filtered
9. 9
   농축concentrated in vacuo

실험 절차

To 1,3-dimethyl-4-nitro-1H-pyrazole-5-carboxylic acid (1.08 g, 5.84 mmol) in anhydrous dichloromethane (DCM) (25 mL) and DMF (0.5 mL) was added dropwise oxalyl chloride (0.74 mL, 8.77 mmol, 1.5 eq.) over 10 minutes. The reaction mixture was stirred at RT under N2 for 17 hours. Volatile solvent was evaporated in vacuo, and the crude material dissolved in anhydrous THF (20 mL) and acetone (10 mL). Concentrated aqueous ammonium hydroxide (5.0 mL, 128.4 mmol, 22 eq.) was added slowly, and the reaction mixture was stirred at RT for 16 hours. The reaction mixture was concentrated in vacuo, and the residue was diluted with ethyl acetate. The organic layer was washed with saturated aqueous solution of sodium bicarbonate, water and brine, dried (Na2SO4), filtered and concentrated in vacuo. Trituration from ether-heptane afforded the desired product as a white solid (550.0 mg, 51.5%). 1H NMR (DMSO-d6, 500 MHz) δ ppm 8.39 (broad s, 1H), 8.21 (broad s, 1H), 3.77 (s, 3H), 2.42 (s, 3H).

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