반응 #3716

반응 방정식

propargyl bromide

2-(t-butyl)-5-(2,6-dichloro-4-pyridyl)-1,2,4-triazolin-3-one

K2CO3

→

2-(t-butyl)-5-(2,6-dichloro-4-pyridyl)-4-propargyl-1,2,4-triazolin-3-one

용매

toluene

ethyl acetate

ethyl acetate

반응 조건

후처리

1. 1
   온도The mixture was heated
2. 2
   workup.ADDITIONwas added
3. 3
   온도Refluxing
4. 4
   온도The mixture was cooled
5. 5
   세척washed with 25 mL of water
6. 6
   건조dried over MgSO4
7. 7
   workup.WAITReomoval of the solvent left 2.18 g of crude product as a reddish solid
8. 8
   기타purified by flash chromatography first on a silica gel column
9. 9
   세척on a neutral alumina column eluted portionwise in both cases with ether hexane mixtures
10. 10
    workup.ADDITIONcontaining successively greater percentages of ether

실험 절차

To 2.06 g (7.2 mmol) of crude 2-(t-butyl)-5-(2,6-dichloro-4-pyridyl)-1,2,4-triazolin-3-one were added 30 mL of ethyl acetate, 1 drop of water, and 1.00 g (7.30 mmol) of powdered K2CO3. The mixture was heated to reflux and after 15 min 1.10 g (7.4 mmol) of an 80% by weight solution of propargyl bromide in toluene was added. Refluxing was continued for 2.5 hours. The mixture was cooled, diluted with 175 mL of ethyl acetate, washed with 25 mL of water, and dried over MgSO4. Reomoval of the solvent left 2.18 g of crude product as a reddish solid. The crude product was combined with 0.69 g of material from another run and purified by flash chromatography first on a silica gel column and then on a neutral alumina column eluted portionwise in both cases with ether hexane mixtures containing successively greater percentages of ether to afford 0.97 g of 2-(t-butyl)-5-(2,6-dichloro-4-pyridyl)-4-propargyl-1,2,4-triazolin-3-one (Compound 1) as a white solid, m.p. 107°-109° C. 1H-NMR (CDCl3)∂1.6 (9H,s), 2.45 (1H,t), 4.6 (2H,d), 7.75 (2H,s).

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