تفاعل #742297

معادلة التفاعل

2-(Ethoxymethylene)malononitrile

(2,6-Dichlorophenyl)hydrazine hydrochloride

NaOH

→

product

المردود 94.5%

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

المردود 94.5%

المذيبات

EtOAc

ظروف التفاعل

المعالجة

1. 1
   أخرىThe organic layer separated
2. 2
   غسيلwashed with water (50 mL), brine (50 mL)
3. 3
   تجفيفdried (MgSO4)
4. 4
   ترشيحfiltered
5. 5
   تركيزconcentrated
6. 6
   أخرىwas suspended in methanol (50 mL) under nitrogen at −5° C
7. 7
   درجة الحرارةheated
8. 8
   درجة الحرارةat reflux under nitrogen for 2 hours
9. 9
   درجة الحرارةto cool
10. 10
    أخرىevaporated to dryness

الإجراء التجريبي

(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.

المصدر