تفاعل #213959

معادلة التفاعل

sulfuric acid

2-chloropyridine

semicarbazide hydrochloride

2-ethoxyethanol

2-ethoxyethanol

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product

المردود 59.0%

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one

المردود 59.0%

المذيبات

water

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONA mixture of 50 g
2. 2
   درجة الحرارةto reflux
3. 3
   workup.ADDITIONtreated with a solution of 1 ml
4. 4
   درجة الحرارةThe resulting solution was refluxed for 18 hr
5. 5
   درجة الحرارة, cooled to about 60°
6. 6
   workup.ADDITIONtreated with 150 ml
7. 7
   درجة الحرارةcooled to 0°
8. 8
   أخرىand the solid was collected on a filter
9. 9
   غسيلThe solid was washed well with water
10. 10
    أخرىdried under reduced pressure

الإجراء التجريبي

A mixture of 50 g. (0.44 mole) of 2-chloropyridine and 98.22 g. (0.88 mole) of semicarbazide hydrochloride in 150 ml. of 2-ethoxyethanol was heated to reflux and then treated with a solution of 1 ml. of concentrated sulfuric acid (36 N) in 5 ml. of 2-ethoxyethanol. The resulting solution was refluxed for 18 hr., cooled to about 60°, and treated with 150 ml. of water. The mixture was stirred, cooled to 0°, and kept 0.5 hr. and the solid was collected on a filter. The solid was washed well with water and dried under reduced pressure, to give 35.0 g (59%) of product, m.p. 230°-231°, which was sufficiently pure to be used for the next step.

المصدر