Реакция #1876805

Уравнение реакции

hydrochloric acid

5-benzylamino-3-bromo-1-(2′-methoxyethyl)-4-nitropyrazole

→

4,5-diamino-1-(2′-methoxyethyl)pyrazole

4,5-diamino-1-(2′-methoxyethyl)pyrazole dihydrochloride

Растворители

ethanol

Условия реакции

Обработка

1. 1
   ДругоеThe catalyst is then removed by filtration
2. 2
   Промывкаwashed with ethanol
3. 3
   Другоеthe filtrate is evaporated under reduced pressure
4. 4
   ДругоеA crude orange-coloured solid (2.8 g) is thus obtained
5. 5
   Другоеis triturated in EtOAc (20 ml) for 1 hour
6. 6
   ФильтрацияThe solid is then filtered off
7. 7
   Промывкаwashed with cold EtOAc (20 ml)
8. 8
   Другоеdried under vacuum

Методика

A mixture of 5-benzylamino-3-bromo-1-(2′-methoxyethyl)-4-nitropyrazole (4 g, 2.8 mmol) in ethanol (500 ml) containing a 10% Pd/C catalyst (Johnson-Mattey Type 487, dry weight 0.5 g) and 36% hydrochloric acid (0.57 g, 5.6 mmol) is hydrogenated in a Parr Autoclave (1 l) at 1 MPa for 1 hour. The catalyst is then removed by filtration and washed with ethanol, and the filtrate is evaporated under reduced pressure. A crude orange-coloured solid (2.8 g) is thus obtained, and is triturated in EtOAc (20 ml) for 1 hour. The solid is then filtered off and washed with cold EtOAc (20 ml) and then dried under vacuum to give the 4,5-diamino-1-(2′-methoxyethyl)pyrazole in the form of a beige-coloured solid (0.7 g, 27%).

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