3,5-Dimethyl-4-nitro-1H-pyrrole-2-carboxaldehyde

Starting material 2-formyl-3, 5-dimethyl-1-hydropyrrole (5.0 g, 1.0e) was added in portions to concentrated sulfuric acid (60 ml), kept at a temperature of 0 to -5 °C. The mixture was a reddish brown clear liquid, to which was added potassium nitrate (4.35 g, 1.05 e) in portions, kept at a temperature of -8 to -2 °C. After the addition, the mixture was reacted at about -7 °C for 20 min, then was warmed to room temperature and reacted for 20 min. Once the reaction was completed as indicated by TLC, the reaction solution was added into 1500 ml of ice water, and an earthy yellow solid was precipitated. The precipitate was collected by filtration, washed with water to neutral, and dried to obtain a grey product, 6.7 g (yield 98percent).a. General procedure: 2-formyl-3, 5-dimethyl-1-hydropyrrole (5.0 g, 40 mmol) wasadded in portions to 60 ml of concentrated sulfuric acid andstirred at 0C to generate a reddish brown clear liquid. Potassiumnitrate (4.35 g, 43 mmol) was added into the mixture in portionsat 7 C. After the addition, the mixture was stirred at 7 C for20 min, then was warmed to room temperature and reacted for20 min. Once the reaction was completed as indicated by TLC, thereaction solution was added into 1500 ml of ice water, and anearthy yellowsolid was precipitated. The precipitate was collectedby filtration, washed with water to neutral, and dried to give 2-formyl-3, 5-dimethyl-4-nitro-1-hydropyrrole as a gray product(6.7 g, yield 98percent)3, 5-dimethyl-2-pyrrolealdehyde I as a raw material (5 g, 40 mmol) was dissolved in 60 mL concentrated sulfuric acid, then the temperature of the system was lowered to —10° C., at which temperature KNO3 (4.35 g, 42 mmol) was slowly added in batches over about 2 h, during which the temperature was maintained at —10° C., and the solution was further stirred for about 2 h at this temperature after the addition of KNO3 was completed. Upon completion of the reaction as indicated by TLC, the resultant solution was added to 1 pL ice water, and extracted twice with a total of 1 L ethyl acetate. The organic layer was washed with a saturated NaC1 solution, dried over anhydrous sodium sulfate, and filtered. Then the organic solvents were evaporated oil at reduced pressure to obtain 7 g crude product, which was added to 10-20 mL ethyl acetate, followed by vigorous stirring, to obtain 5 g pure product of the target compoundII.The crude 2-aldehyde-3, 5-dimethyl-1-hydrogenpyrrole (5.0 g, 1.0 ) was added portionwise to concentrated sulfuric acid (60 ml) at a temperature of 0 ° C to 5 ° C, , Potassium nitrate (4.358, 1.056) was added in portions and the temperature was maintained at -8 to 2 ° C, after the addition, -7 ° C reaction 20min, rose to room temperature reaction 20min, TLC detection reaction is completed, the reaction solution added to 1500ml ice water, the precipitate yellow solid, filtered, washed to neutral, dry gray product 6.7g (yield 98percent)

Molecular Weight:168.15
XLogP3:1.1
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:168.05349212
Monoisotopic Mass:168.05349212
Topological Polar Surface Area:78.7
Heavy Atom Count:12
Complexity:201
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes