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

Temperature

10 °C

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.

1. temperaturewise maintaining the temperature between 5 and 10° C. (formation of a yellow precipitate)
2. additionAfter complete addition the mixture
3. customThe crude product separated as a yellow solid, which
4. filtrationwas filtered
5. dissolutiondissolved in dichloromethane
6. dry with materialThe solution was dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe crude product was purified on a silica eluting with a gradient
10. customformed from heptane and ethyl acetate
11. customEvaporation of the product fractions

ORD record

ord-8c051400008a43a2aac11fcd8abecca6

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08067598B2