Water → (R)-1-Boc-2-methylpyrrolidine

Temperature

0 °C

A solution of 2-(S)-methanesulfonyloxymethyl-pyrrolidine-1-carboxylic acid tert-butyl ester (compound (3), 4.6 g, 0.016 mol) in anhydrous tetrahydrofuran (50 mL, THF) was cooled to 0° C. 1.0 M Lithium triethylborohydride in THF (38 mL, 3.17 g, 0.029 mol) was added dropwise to the reaction mixture while maintaining reaction temperature below 0° C. The reaction mixture was refluxed for overnight (˜11 hour). HPLC showed absence of starting material. Reaction mixture was cooled to 0° C. and ethyl acetate (50 mL) was slowly added followed by addition of distilled water (50 mL) while maintaining temperature below 10° C. The organic layer was separated and washed with distilled water (2×50 mL), 1 M H3PO4(2×50 mL) and saturated NaHCO3 (2×50 mL), dried over MgSO4, filtered, and concentrated to leave an oily residual product (2.46 g, 53.5% yield). 1H NMR (CDCl3): δ 1.16 (d, 3H, CH3), 1.47 (s, 9H, 3×CH3), 1.50–1.82 (m, 2H, CH2), 1.84–2.03 (m, 2H, CH2), and 3.86 (m, 1H, CH).

1. temperaturewhile maintaining
2. customreaction temperature below 0° C
3. temperatureThe reaction mixture was refluxed for overnight (˜11 hour)
4. customReaction mixture
5. temperaturewhile maintaining temperature below 10° C
6. customThe organic layer was separated
7. washwashed with distilled water (2×50 mL), 1 M H3PO4(2×50 mL) and saturated NaHCO3 (2×50 mL)
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated

ORD record

ord-f01c7246986b4f51bc3baa88a0b698b8

Source dataset

uspto-grants-2007_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07244852B2