反应详情

583.7 g of hydroxylamine hydrochloride was dissolved in 2 l of a 4N aqueous solution of sodium hydroxide. 2 l of ethanol was added to the solution under cooling with ice. A 1:1 mixture of a 4N aqueous solution of sodium hydroxide and ethanol was added to the solution so that the pH thereof was adjusted to 10.0. 1,380 g of ethyl pivaloylacetate and a 1:1 mixture of a 4N aqueous solution of sodium hydroxide and ethanol were simultaneously added dropwise to the solution in such a manner that the pH of the reaction solution was 10±0.2 and the temperature thereof was 0° to 5° C. After the dropwise addition was finished, the reaction mixture was stirred at room temperature for 2 hours, and then poured into 6 kg of concentrated hydrochloric acid. The reaction mixture was allowed to stand for 12 hours. The resulting crystal was filtered off, thoroughly washed with water, and then dried. (Yield: 770 g (68.2%); m.p.: 99°-101° C.)

1. temperatureunder cooling with ice
2. additionwas added to the solution so that the pH
3. additionwere simultaneously added dropwise to the solution in such a manner that the pH of the reaction solution
4. customthereof was 0° to 5° C
5. additionAfter the dropwise addition
6. waitto stand for 12 hours
7. filtrationThe resulting crystal was filtered off
8. washthoroughly washed with water
9. customdried