反应详情

The hydrazine (Intermediate 55, 1.5 g, 7.1 mmol) was dissolved in dry toluene (30 ml) under nitrogen at room temperature. Sodium cyanate (1.6 g, 24.6 mmol) was added followed by trifluoroacetic acid (1.7 ml, 22,1 mmol). The reaction was stirred for 2.25 h after which the reaction was poured into saturated sodium bicarbonate solution (100 ml) and extracted with ethyl acetate (4×(100 ml). The combined extracts were dried (Na2SO4) and concentrated in vacuo to give a white solid. The crude material was triturated with ether (2×100 ml) to give the title compound (Intermediate 56, 1.41 g, 78%) as a colourless powder, m.p. 169°-70°.

1. extractionextracted with ethyl acetate (4×(100 ml)
2. dry with materialThe combined extracts were dried (Na2SO4)
3. concentrationconcentrated in vacuo
4. customto give a white solid
5. customThe crude material was triturated with ether (2×100 ml)