反应详情

To a homogeneous solution of 15.6 g. (80 mM) of piperazine hexahydrate and 13.8 g. (80 mM) of 47% hydrobromic acid in 40 ml. of ethanol there were added dropwise at room temperature another solution of 6.3 g. (40 mM) of 3-(Furan-2-yl)-acryloylchloride in 10 ml. of tetrahydrofuran. After stirring for two hours at room temperature, the resulting solution was heated at 80° for two hours. Then the solution was cooled with ice and the forming crystals of piperazine hydrobromide were filtered off. The filtrate was condensed under reduced pressure and 80 ml. of 2 N-hydrochloric acid was added into the residue. After neutral substances were removed by extraction with ethyl acetate, the resulting solution was made alkaline with 5 N sodium hydroxide and extracted again with ethyl acetate. After drying over anhydrous sulfate, the combined extracts were condensed to give 4.62 g. of 3-(Furan-2-yl)-acryloylpiperazine (56% yield).

1. temperaturethe resulting solution was heated at 80° for two hours
2. temperatureThen the solution was cooled with ice
3. filtrationthe forming crystals of piperazine hydrobromide were filtered off
4. customcondensed under reduced pressure and 80 ml
5. customAfter neutral substances were removed by extraction with ethyl acetate
6. extractionextracted again with ethyl acetate
7. dry with materialAfter drying over anhydrous sulfate
8. customcondensed
9. customto give 4.62 g