Triethylamine → 8-Chloro-6-(1-ethylpyrazol-5-yl)oxycarbonyl-5-methylthiochroman-4-one

関与物質

反応条件

反応手順

A mixture containing 2.0 g (7.8 mmol) of 6-carboxy-8-chloro-5-methylthiochroman-4-one and 2.8 g (3.0 eq., 24 mmol) of thionyl chloride was stirred under heat at 40° C. for 2 hours. After the completion of the reaction, excess thionyl chloride was removed under reduced pressure. Then, the resultant acid chloride was dissolved in 10 ml of methylene chloride, and 0.96 g (1.1 eq., 8.6 mmol) of 1-ethyl-5-hydroxypyrazole and 0.95 ml (9.41 mmol) of triethylamine were added. The mixture was stirred at room temperature for 3 hours. The reaction mixture was diluted with methylene chloride, washed with diluted hydrochloric acid and with a saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate, and the solvent was distilled off to give 2.29 g (yield 84%) of 8-chloro-6-(1-ethylpyrazol-5-yl)oxycarbonyl-5-methylthiochroman-4-one.

情報源と証拠