Reaktion #435606

Reaktionsgleichung

3-ethyl-4-nitro-1H-pyrazole-5-carboxamide

sodium carbonate

2-bromoethyl methyl ether

CH2Cl2

→

5-Ethyl-1-(2-methoxyethyl)-4-nitro-1H-pyrazole-3-carboxamide

Lösungsmittel

THF

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturunder reflux
3. 3
   SonstigeThe resultant organic and aqueous layers were separated
4. 4
   ExtraktionThe aqueous phase was extracted with CH2Cl2 (22.5 L)
5. 5
   workup.DISTILLATIONthe combined organic solution was distilled under atmospheric pressure
6. 6
   workup.WAITThe cooled mixture was granulated at ambient temperature for 2 hours
7. 7
   Filtrationfiltered
8. 8
   Waschenwashed with ethyl acetate (2.5 L)

Vorschrift

A mixture of 3-ethyl-4-nitro-1H-pyrazole-5-carboxamide (2.5 kg, 13.6 Mol), sodium carbonate (1.8 Kg, 17.0 Mol) and 2-bromoethyl methyl ether (1.98 kg, 14.2 Mol) in THF (22.5 L) and water (2.5 L) was heated under reflux and stirred for 20 hours. The mixture was cooled to ambient temperature and CH2Cl2 (67.5 L) and water (22.5 L) were added. The resultant organic and aqueous layers were separated. The aqueous phase was extracted with CH2Cl2 (22.5 L) and the combined organic solution was distilled under atmospheric pressure and replaced with ethyl acetate (33 L) to a final volume of 17 L. The cooled mixture was granulated at ambient temperature for 2 hours, filtered and washed with ethyl acetate (2.5 L). This afforded 5-ethyl-1-(2-methoxyethyl)-4-nitro-1H-pyrazole-3-carboxamide as a white crystalline solid, 2.10 kg, 57%. m.p.=140° C. Found: C, 44.46; H, 5.79; N, 23.01. C9H14N4O4 requires C, 44.63; H, 5.79; N, 23.14%.

Quelle