反应详情

During a 30 minute period a solution of 3-chloro-2-methylaniline (8.3 g, 0.2 mole) in thiophene (100 ml) was added dropwise to a stirred mixture of t-butyl nitrite (30.9 g, 0.3 mole) and copper powder (10.0 g, 0.16 mole) in thiophene (1.9 l). After complete addition, the mixture was heated at 60° for two hours, then at reflux for approximately 18 hours. The reaction mixture was cooled, filtered, and the filtrate evaporated under reduced pressure to leave a residue. The residue was subjected to column chromatography on silica gel, elution with toluene. The toluene was evaporated under reduced pressure to leave a residue which was rechromatographed on silica gel, elution with n-heptane. The fractions which contained the desired product was combined and evaporated under reduced pressure to leave an oil. The oil was purified by distillation under reduced pressure to yield 2-(3-chloro-2-methylphenyl)thiophene (25.9 g, 62.2% yield, bp 93°/0.1 mm). This experiment is designated Run 5/1 in the following tabulation of several experiments conducted with and without copper, but under otherwise similar conditions.

1. additionAfter complete addition
2. temperaturethe mixture was heated at 60° for two hours
3. temperatureat reflux for approximately 18 hours
4. temperatureThe reaction mixture was cooled
5. filtrationfiltered
6. customthe filtrate evaporated under reduced pressure
7. customto leave a residue
8. washThe residue was subjected to column chromatography on silica gel, elution with toluene
9. customThe toluene was evaporated under reduced pressure
10. customto leave a residue which
11. customwas rechromatographed on silica gel, elution with n-heptane
12. customevaporated under reduced pressure
13. customto leave an oil
14. distillationThe oil was purified by distillation under reduced pressure