反应详情

To a suspension of 250 g (1.89 mol) of AlCl3 (anhydrous powder) in 350 ml of CHCl3, 129 g (0.85 mol) of 5-methyl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one in 130 ml of CHCl3 was added at 0° C. over a period of 0.5 hours. The reaction mixture was stirred for 10 min at this temperature; then a solution of 46.7 ml of Br2 (0.91 mol) in 90 ml of CHCl3 was added dropwise over a period of 1 hour. The resulting mixture was stirred for 1 hour at room temperature and, then, poured over 2000 cm3 of ice. The organic layer was separated. The aqueous layer was extracted with 4×200 ml of CH2Cl2. The combined organic fractions were washed with 1000 ml of the saturated aqueous Na2CO3, dried over K2CO3, passed through short column with Silica Gel 60 (40-63 μm, d 40 mm, l 50 mm), and evaporated to dryness. Fractional distillation gave white crystalline product, b.p. 128° C./0.8 mm Hg. Yield 185 g (94%).

1. additionwas added at 0° C. over a period of 0.5 hours
2. stirringThe resulting mixture was stirred for 1 hour at room temperature
3. customThe organic layer was separated
4. extractionThe aqueous layer was extracted with 4×200 ml of CH2Cl2
5. washThe combined organic fractions were washed with 1000 ml of the saturated aqueous Na2CO3
6. dry with materialdried over K2CO3
7. customevaporated to dryness
8. distillationFractional distillation
9. customgave white crystalline product, b.p. 128° C./0.8 mm Hg