反应详情

Hydrazine monohydrate (4.8 g, 96 mmol) was dissolved in industrial methylated spirits (160 mL) and cooled to 0° C. before ethyl trifluoroacetate (14 g, 100 mmol; Aldrich Chemical Company, Inc., Milwaukee, Wis.) was added dropwise. The resulting reaction mixture was then warmed to ambient temperature and stirred for 1 hour. After this time, the solvent was removed under vacuum and the residue re-dissolved in industrial methylated spirits (100 mL). Formamidine acetate (9.9 g, 95 mmol; Aldrich Chemical Company, Inc., Milwaukee, Wis.) was then added and the reaction mixture heated to 80° C. for 2.5 hours. The reaction was then cooled to ambient temperature and the solvent removed under vacuum. To the residue was then added NaHCO3 (aq.) (100 mL), and the product was extracted with ethyl acetate (2×100 mL), dried over MgSO4, filtered and the solvent removed under vacuum. The crude product was then purified by flash chromatography (1:3 hexane/ethyl acetate), giving ˜10 g of a pale peach oil, which crystallised on standing overnight. The crystals were then filtered, washed with hexane and dried overnight in an oven to afford (I-15a) as colorless crystals (8.73 g, 66% yield): 1H NMR (400 MHz, DMSO-d6): δ 8.81 (1H).

1. additionwas added dropwise
2. customThe resulting reaction mixture
3. customAfter this time, the solvent was removed under vacuum
4. dissolutionthe residue re-dissolved in industrial methylated spirits (100 mL)
5. temperaturethe reaction mixture heated to 80° C. for 2.5 hours
6. temperatureThe reaction was then cooled to ambient temperature
7. customthe solvent removed under vacuum
8. extractionadded NaHCO3 (aq.) (100 mL), and the product was extracted with ethyl acetate (2×100 mL)
9. dry with materialdried over MgSO4
10. filtrationfiltered
11. customthe solvent removed under vacuum
12. customThe crude product was then purified by flash chromatography (1:3 hexane/ethyl acetate)
13. customgiving ˜10 g of a pale peach oil, which
14. customcrystallised
15. waiton standing overnight
16. filtrationThe crystals were then filtered
17. washwashed with hexane
18. customdried overnight in an oven