反应详情

温度

20 °C

A mixture of ethyl-4-β-carboxyethylthio-2-methyl-1,3-cyclohexadiene-1-carboxylate (121.3 g, 0.449 mole) in toluene is stirred at 20° C., treated sequentially with 5.0 ml methanesulfonic acid and portionwise over a 5 minute period with trifluoroacetic anhydride (94.3 g, 0.449 mole) and allowed to stir at ambient temperatures for 18 hours. The resultant reaction mixture is quenched with a 1:1 mixture of ethyl acetate and water and stirred for 15 minutes. The phases are separated. The organic phase is washed with water and concentrated in vacuo to give a residue. Crystallization of the residue from isopropanol/heptane affords the title product as a yellow solid, 90.1 g, (79.5% yield), mp 99°-100° C., identified by 1HNMR and mass spectral analyses.

1. stirringto stir at ambient temperatures for 18 hours
2. customThe resultant reaction mixture
3. customis quenched with a 1:1 mixture of ethyl acetate and water
4. stirringstirred for 15 minutes
5. customThe phases are separated
6. washThe organic phase is washed with water
7. concentrationconcentrated in vacuo
8. customto give a residue
9. customCrystallization of the residue from isopropanol/heptane