反应详情

温度

0 °C

Sodium hydroxide (16.0 g, 400 mmol) was dissolved in absolute ethanol (1 L) at 60° C. The solution was cooled to 0° C. and treated portion-wise with ethyl ethanimidoate hydrochloride (50 g, 400 mmol); after 10 minutes, tert-butyl hydrazinecarboxylate (52.9 g, 400 mmol) was added in a single portion. The reaction mixture was stirred at 70° C. for 2.5 hours, then cooled to 20° C. and filtered. The filtrate was concentrated in vacuo and treated with tert-butyl methyl ether (500 mL) and ethanol (20 mL). After seeding, the mixture was allowed to stir for 18 hours, whereupon the precipitated solid was collected via filtration and washed with ice-cold tert-butyl methyl ether (500 mL). The solid was dissolved in 2-methyltetrahydrofuran:methanol (9:1 mixture, 300 mL), and the solution was concentrated to dryness. The residue was washed with diethyl ether (3×200 mL) to afford the product as a very pale yellow solid. Yield; 50.2 g, 290 mmol, 72%. LCMS m/z 174.3 [M+H]+. 1H NMR (500 MHz, CD3OD) δ 1.88 (s, 3H), 1.47 (s, 9H).

1. temperaturecooled to 20° C.
2. filtrationfiltered
3. concentrationThe filtrate was concentrated in vacuo
4. additiontreated with tert-butyl methyl ether (500 mL) and ethanol (20 mL)
5. stirringto stir for 18 hours, whereupon the precipitated solid
6. filtrationwas collected via filtration
7. washwashed with ice-cold tert-butyl methyl ether (500 mL)
8. dissolutionThe solid was dissolved in 2-methyltetrahydrofuran:methanol (9:1 mixture, 300 mL)
9. concentrationthe solution was concentrated to dryness
10. washThe residue was washed with diethyl ether (3×200 mL)
11. customto afford the product as a very pale yellow solid