反应详情

温度

100 °C

To a suspension of N′-(3-methyl-5-nitropyridin-2-yl)acetohydrazide (Step 67.2) (41.5 g, 198 mmol) in dioxane (180 mL) was added AcOH (35 mL) and the reaction mixture was stirred for 3 hr at 100° C. The reaction mixture was cooled RT and the crystallization was facilitated by the addition of Et2O (700 mL) over a period of 3 hr. After stirring the suspension for 3 hr at 0° C., the crystals were collected, washed with Et2O and dried to afford the title product (23.4 g, 119 mmol, 60% yield) as a light yellow solid. tR: 0.51 min (LC-MS 2); ESI-MS: 193 [M+H]+ (LC-MS 2); TLC (EtOAc/MeOH 9:1) Rf=0.35; 1H NMR (400 MHz, DMSO-d6) δ ppm 2.60 (s, 3H) 2.80 (s, 3H) 7.87 (d, J=1.9 Hz, 1H) 9.45 (d, J=1.8 Hz, 1H).

1. temperatureThe reaction mixture was cooled RT
2. customthe crystallization
3. additionwas facilitated by the addition of Et2O (700 mL) over a period of 3 hr
4. stirringAfter stirring the suspension for 3 hr at 0° C.
5. customthe crystals were collected
6. washwashed with Et2O
7. customdried