تفاعل #1809909

معادلة التفاعل

chloroform

4-(3-methyl-5-oxo-2-pyrazolin-1-yl)benzoic acid

ethyl chlorocarbonate

→

1-(4-hydroxymethylphenyl)-3-methyl-2-pyrazolin-5-one

المردود 35.0%

المذيبات

triethylamine

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةfurther under ice-cooling
2. 2
   أخرىAfter evaporation of the solvent
3. 3
   workup.DISSOLUTIONthe residue was dissolved in 200 ml of THF
4. 4
   ترشيحthe insolubles were filtered off
5. 5
   workup.DISSOLUTIONa solution of 2.08 g of NaBH4 dissolved in 60 ml of water
6. 6
   workup.ADDITIONwas added dropwise into the filtrate
7. 7
   أخرىAfter evaporation of the solvent, water
8. 8
   workup.ADDITIONwas added to the residue
9. 9
   استخلاصextracted with chloroform
10. 10
    أخرىThe organic layer was dried
11. 11
    تركيزconcentrated
12. 12
    أخرىpurified on silica gel column chromatograph with the use of chloroform-ethanl (100:1) as eluant
13. 13
    أخرىfollowed by recrystallization from chloroform-ethyl ether

الإجراء التجريبي

Into 250 ml of anhydrous chloroform were added 5.0 g of 4-(3-methyl-5-oxo-2-pyrazolin-1-yl)benzoic acid and 25 ml of triethylamine and, further under ice-cooling, 12.5 ml of ethyl chlorocarbonate was added dropwise into the mixture. After evaporation of the solvent, the residue was dissolved in 200 ml of THF, the insolubles were filtered off, and then a solution of 2.08 g of NaBH4 dissolved in 60 ml of water was added dropwise into the filtrate, followed by stirring at room temperature for 2 hours. After evaporation of the solvent, water was added to the residue, and the mixture was adjusted with dil. hydrochloric acid to pH 4-5 and then extracted with chloroform. The organic layer was dried, concentrated and purified on silica gel column chromatograph with the use of chloroform-ethanl (100:1) as eluant, followed by recrystallization from chloroform-ethyl ether to give 1.16 g of 1-(4-hydroxymethylphenyl)-3-methyl-2-pyrazolin-5-one as colorless crystals.

المصدر