Hydrochloric Acid → 2-Methyl-5-[(E)-2-nitroethenyl]thiophene

Participants

Reaction Conditions

Reaction Steps

A solution of 10.3 g (80 mmol) 5-methyl-2-thiophenecarboxaldehyde (commercially available) and 13.5 mL nitromethane in 160 mL methanol was cooled to −5° C. A 50% sodium hydroxide solution (80 mL) was added drop wise maintaining the temperature between 5 and 10° C. (formation of a yellow precipitate). After complete addition the mixture was stirred at 10° C. for 1 h. The suspension was poured onto an ice-cold solution of HCl 37% (340 mL) and water (560 mL). The crude product separated as a yellow solid, which was filtered and dissolved in dichloromethane. The solution was dried over Na2SO4, filtered and concentrated in vacuo. The crude product was purified on a silica eluting with a gradient formed from heptane and ethyl acetate. Evaporation of the product fractions yielded 6.9 g (51%) of the title compound as yellow solid.

Provenance & Evidence