反应详情

Sodium (257 mg, 11 mmol) was dissolved in absolute ethanol (50 ml) with stirring under argon. When the sodium had thoroughly dissolved, guanidine hydrochloride (2) (502 mg, 5 mmol) and diethyl fluoromalonate (1) (790 mg, 4.4 mmol) were added. The solution was left to stir at room temperature overnight. A condenser was then attached to the flask and the solution was refluxed under argon for 4.5 hours. The solution was cooled to room temperature and concentrated. The residue was redissolved in 20 ml hot H2O and acidified to pH 4. The mixture was cooled on ice and the precipitate was collected, yielding (3) as a peach colored solid (618 mg, 96%): MS (70 eV, EI)m/z (relative intensity) 146(M+, 100), 18 (95), 172 (26), 17 (24), 300 (21); IR (mull, cm-1) 3363, 1695, 1601, 1420, 1208, 677, 666; UV (MeOH, nm) 206(3,840), 235(3,380), 270(11,600). Exact Mass Calcd for C4H4N3O2F: 146.0366. Found: 146.0371.

1. waitThe solution was left
2. stirringto stir at room temperature overnight
3. customA condenser was then attached to the flask
4. temperaturethe solution was refluxed under argon for 4.5 hours
5. concentrationconcentrated
6. dissolutionThe residue was redissolved in 20 ml hot H2O
7. temperatureThe mixture was cooled on ice
8. customthe precipitate was collected