Diisopropylamine → Methyl 5-(3,5-dimethoxypyridin-4-yl)-5-(1,1-dimethylethylsulfinamido)pentanoate

Temperature

-78 °C

A cooled (−78° C.) slightly yellow solution of diisopropylamine (1.946 g; 19.23 mmol) in anh. THF (85 ml), under nitrogen, was treated dropwise with a solution of 1.6 M n-BuLi in hexanes (12.0 ml; 19.23 mmol). The resulting slightly yellow solution was further stirred at −78° C. for 20 min. A slightly yellow solution of 3,5-dimethoxypyridine (2.433 g; 17.48 mmol) in anh. THF (7 ml) was then added dropwise. The resulting yellow heterogeneous mixture was further stirred at −78° C. for 30 min. A yellow solution of methyl 5-((tert-butylsulfinyl)imino)pentanoate (4.080 g; 17.48 mmol) in anh. THF (8 ml) was then added to the cooled reaction mixture, and stirring at −78° C. was continued for 90 min. The resulting orange reaction mixture was treated successively with aq. sat. NH4Cl (29 ml), Et2O (100 ml) and water (25 ml). The separated yellow organic layer was then washed with brine (30 ml), dried over anh. MgSO4, filtered, and concentrated to dryness under reduced pressure. Purification by FC (DCM/MeOH=20/1) afforded methyl 5-(3,5-dimethoxypyridin-4-yl)-5-(1,1-dimethylethylsulfinamido)pentanoate as a yellow oil. LC-MS (conditions B): tR=0.59 min.; [M+H]+: 373.00 g/mol.

1. stirringThe resulting yellow heterogeneous mixture was further stirred at −78° C. for 30 min
2. stirringstirring at −78° C.
3. waitwas continued for 90 min
4. washThe separated yellow organic layer was then washed with brine (30 ml)
5. dry with materialdried over anh. MgSO4
6. filtrationfiltered
7. concentrationconcentrated to dryness under reduced pressure
8. customPurification by FC (DCM/MeOH=20/1)

ORD record

ord-1642617f16934d86b57567e0cda492b1

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09242970B2