反应详情

2 g of 1-{4-[5-(2-fluorobiphenyl-4-yl)[1,2,4]oxadiazol-3-yl]benzyl}piperidine-4,4-dicarboxylic acid benzyl ester 3,3-dimethyl-2-oxobutyl ester are added into round bottomed flask containing a solvent mixture of ethyl acetate/tetrahydrofuran [1/0.5] and stirred at room temperature to get a clear solution. Then 40 mL of ethanol are added followed by 0.6 g Pd/CaCO3. The mixture is stirred under hydrogen gas. After 30 mins 0.2 g of Pd/CaCO3 are added to the above reaction mixture and stirring under hydrogen is continued. Once the reaction gets completed 4 g of silica gel are added and the mixture stirred at RT for 10 mins, cooled to 0-5° C. and stirred for 20-30 mins. The slurry is filtered and washed with 40 mL ethyl acetate. The product along with Pd/CaCO3 on the funnel was leached with 200 mL, then 250 mL of a dichloromethane/methanol [2:1] mixture at RT and filtered. The product containing filtrate is concentrated and dried under vacuum at 35-40° C. to yield 1-{4-[5-(2-fluorobiphenyl-4-yl)[1,2,4]oxadiazol-3-yl]benzyl}-piperidine-4,4-dicarboxylic acid (3,3-dimethyl-2-oxobutyl)ester (62).

1. additioncontaining
2. customto get a clear solution
3. stirringThe mixture is stirred under hydrogen gas
4. stirringstirring under hydrogen
5. additionare added
6. stirringthe mixture stirred at RT for 10 mins
7. temperaturecooled to 0-5° C.
8. stirringstirred for 20-30 mins
9. filtrationThe slurry is filtered
10. washwashed with 40 mL ethyl acetate
11. filtration250 mL of a dichloromethane/methanol [2:1] mixture at RT and filtered
12. additionThe product containing filtrate
13. concentrationis concentrated
14. customdried under vacuum at 35-40° C.