반응 #742297

반응 방정식

2-(Ethoxymethylene)malononitrile

(2,6-Dichlorophenyl)hydrazine hydrochloride

NaOH

→

product

수율 94.5%

5-amino-1-(2,6-dichlorophenyl)-1H-pyrazole-4-carbonitrile

수율 94.5%

용매

EtOAc

반응 조건

후처리

1. 1
   기타The organic layer separated
2. 2
   세척washed with water (50 mL), brine (50 mL)
3. 3
   건조dried (MgSO4)
4. 4
   여과filtered
5. 5
   농축concentrated
6. 6
   기타was suspended in methanol (50 mL) under nitrogen at −5° C
7. 7
   온도heated
8. 8
   온도at reflux under nitrogen for 2 hours
9. 9
   온도to cool
10. 10
    기타evaporated to dryness

실험 절차

(2,6-Dichlorophenyl)hydrazine hydrochloride (5 g, 23.42 mmol) was partitioned between EtOAc (100 mL) and NaOH (2M, aq) (40 mL). The organic layer separated and washed with water (50 mL), brine (50 mL), dried (MgSO4), filtered and concentrated. The resultant oil was suspended in methanol (50 mL) under nitrogen at −5° C. 2-(Ethoxymethylene)malononitrile (2.86 g, 23.42 mmol) added portion-wise over 5 mins and the mixture stiffed at 0° C. for 30 mins. The reaction mixture was allowed to warm to room temperature and then heated at reflux under nitrogen for 2 hours. The reaction mixture was allowed to cool and evaporated to dryness to afford the product (5.60 g, 94%) which was used without further purification. 1H NMR (400 MHz, CDCl3) δ 4.47 (2H, s), 7.43-7.47 (1H, m), 7.51-7.53 (2H, m), 7.73 (1H, s); m/z (ES+) (M+H)+=253; HPLC tR=1.62 min. Alternatively the product was obtained by concentrating the reaction mixture to half volume and allowing the product to crystallise.

출처