反应详情

The hydrazine (Intermediate 33; 910 mg, 4.1 mmol) was dissolved in dry toluene (30 ml) under nitrogen at room temperature. Sodium cyanate (880 mg, 13.5 mmol) was added to the reaction mixture, followed by trifluoroacetic acid (0.95 ml, 12.3 mmol). The reaction was stirred at room temperature for 3 h, then poured into sodium bicarbonate solution (30 ml, 8%) and extracted with ethyl acetate (3×75 ml). The combined dried (Na2SO4), organic phases were concentrated in vacuo to give a yellow oil. The crude material was triturated with ether and hexane to give the title compound (Intermediate 34; 500 mg, 46%) as a white powdery solid m.p. 111°-116°.

1. extractionextracted with ethyl acetate (3×75 ml)
2. dry with materialThe combined dried (Na2SO4), organic phases
3. concentrationwere concentrated in vacuo
4. customto give a yellow oil
5. customThe crude material was triturated with ether and hexane