Diisopropylamine → HCID 178506295, compound

Normal-butyllithium (a 2.76 M solution in hexane, 37.0 mL) was dropwise added to a solution of N,N-diisopropylamine (15.0 mL) in tetrahydrofuran (hereinafter referred to as THF, 200 mL) under a nitrogen atmosphere at −5 to 0° C., and a solution of 2-fluoro-3-iodo-pyridine (21.8 g) in THF (250 mL) was dropwise added to the resulting solution at −78° C., followed by stirring for 15 min. Subsequently, ethyl 2,2,2-trifluoroacetate (14.0 mL) was dropwise added to the reaction solution at −78° C., followed by stirring at the same temperature for 1 hr, and then hydrazine monohydrate (9.5 mL) was added to the reaction solution, followed by stirring at 60° C. for 1 hr. The reaction solution was distributed between ethyl acetate and water, and the organic layer was washed with saturated saline. The organic layer after the washing was dried over anhydrous sodium sulfate, and then the solvent was distilled away. The residue was purified by neutral silica gel column chromatography (hexane/ethyl acetate) to obtain compound (153a) (21.0 g, 69%) as a white solid.

1. customat −5 to 0° C.
2. stirringby stirring at the same temperature for 1 hr
3. stirringby stirring at 60° C. for 1 hr
4. washthe organic layer was washed with saturated saline
5. dry with materialThe organic layer after the washing was dried over anhydrous sodium sulfate
6. distillationthe solvent was distilled away
7. customThe residue was purified by neutral silica gel column chromatography (hexane/ethyl acetate)

ORD record

ord-6d56e2e27f6d403d81352ff9a6e098fc

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09273045B2