Hydrochloric Acid → 2-(4-Chloro-2-nitro-phenylamino)-5-methyl-thiophene-3-carbonitrile

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Reaction Steps

Dissolve 2-amino-5-methyl-thiophene-3-carbonitrile (4.14 g, 30 mmol) and 2,4-dichloronitrobenzene (5.76 g, 30 mmol) in dimethylsulfoxide (70 ml) and stir under nitrogen. Add lithium hydroxide monohydrate (2.0 g, 47.7 mmol) and heat the mixture in an oil bath at room temperature for 18 hours. Pour the mixture into ice water, make acid with 2N HCl, extract into ethyl acetate, dry (MgSO4) and concentrate under reduced pressure. Crystallize from ethanol to give 2-(4-chloro-2-nitro-phenylamino)-5-methyl-thiophene-3-carbonitrile as a yellow solid (2.92 g, 33%): NMR (1H, 300 MHz, CDCl3): δ 9.5 (1H broad), 8.25 (1H,s), 7.45 (1H, d), 7.1 (1H,d), 6.25 (1H, s), 2.5 (3H,s).

Provenance & Evidence