Water → Ammonia

Temperature

-78 °C

To a solution of 0.237 g 8-bromo-2,3-dihydro-1H-3a,5-diaza-cyclopenta[a]indene in 3 ml tetrahydrofuran was added dropwise a 1.6M solution of n-butyl lithium in n-hexane during 15 min at −78° C. The mixture was stirred at −78° C. for 30 min. To the resulting mixture was added (S)-4-Methyl-2,2-dioxo-[1,2,3]oxathiazolidine-3-carboxylic acid tert-butyl ester at once. The mixture was allowed to warm to room temperature during 15 min. The reaction mixture was distributed between water and ethyl acetate, the phases were separated and the organic phase was washed with water and brine, dried over magnesium sulfate and evaporated. The residue was dissolved in 5 mL trifluoro acetic acid and kept at room temperature for 10 min. The solvent was evaporated and the residue was purified by chromatography on silica gel with dichloromethane:methanol:ammonia=9:1:01 to yield 0.045 g (S)-2-(2,3-Dihydro-1H-3a,5-diaza-cyclopenta[a]inden-8-yl)-1-methyl-ethylamine as a white solid.

1. temperatureto warm to room temperature during 15 min
2. customthe phases were separated
3. washthe organic phase was washed with water and brine
4. dry with materialdried over magnesium sulfate
5. customevaporated
6. dissolutionThe residue was dissolved in 5 mL trifluoro acetic acid
7. waitkept at room temperature for 10 min
8. customThe solvent was evaporated
9. customthe residue was purified by chromatography on silica gel with dichloromethane

ORD record

ord-1ad8c208de5c4060887f9197dcea9137

Source dataset

uspto-grants-2003_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06583134B2