反应详情

10.7 g (0.038 mol) of 2-chloro-1-(3,5-di-tert.butyl-4-hydroxyphenyl)-ethanone from step (a) and 4.8 g (0.034 mol) of 4-methylthiosemicarbazide hydrochloride were dissolved in 120 ml of ethanol, and the mixture was heated to boiling for 30 minutes. After cooling, the solvent was removed by distillation under reduced pressure, and the resinous residue was dissolved in 60 ml of warm ethyl acetate. On standing, the product immediately precipitated in crystalline form, and was filtered off and recrystallized again from 150 ml of a mixture of ethyl acetate and methylene chloride (10 : 1).

1. temperaturethe mixture was heated
2. temperatureAfter cooling
3. customthe solvent was removed by distillation under reduced pressure
4. dissolutionthe resinous residue was dissolved in 60 ml of warm ethyl acetate
5. customthe product immediately precipitated in crystalline form
6. filtrationwas filtered off
7. customrecrystallized again from 150 ml of a mixture of ethyl acetate and methylene chloride (10 : 1)