Citric Acid → methyl 2-[1-methyl-5-(methylsulfanyl)-1H-pyrazol-3-yl]-3-(tetrahydro-2H-pyran-4-yl)propanoate

Temperature

-70 °C

To a solution of diisopropylamine (4.0 mL) in tetrahydrofuran (60 mL) was slowly added 1.6M hexane solution (16.1 ml) of n-butyllithium at −70° C. under a nitrogen atmosphere. The reaction mixture was stirred at −70° C. for 15 min, and a solution of methyl [1-methyl-5-(methylsulfanyl)-1H-pyrazol-3-yl]acetate (4.68 g) in tetrahydrofuran (5 mL) was slowly added thereto. The reaction mixture was stirred at −70° C. for 15 min, and 4-(iodomethyl)tetrahydro-2H-pyran (5.80 g) was added thereto. The mixture was stirred overnight at room temperature. To the reaction mixture was added 10% aqueous citric acid solution, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4), and concentrated. The obtained residue was subjected to silica gel column chromatography to give the title compound (2.57 g, yield 37%) as a pale-yellow oil from the fraction eluted with ethyl acetate-hexane (1:1, volume ratio). MS: 299 (MH+).

1. customat −70° C.
2. stirringThe reaction mixture was stirred at −70° C. for 15 min
3. stirringThe mixture was stirred overnight at room temperature
4. extractionthe mixture was extracted with ethyl acetate
5. washThe ethyl acetate layer was washed with saturated brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated

ORD record

ord-9bee50e5b54b46b3a4569546907b0811

Source dataset

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08349886B2