Borane;tetrahydrofuran → tert-Butyl 2-cyclobutylhydrazinecarboxylate

A solution of tert-butyl 2-cyclobutylidenehydrazinecarboxylate (5.0 g, 27.1 mmol) in THF (50 mL) was added dropwise over 1.5 hours to a solution of borane tetrahydrofuran complex (33.9 mL, 33.9 mmol) under a nitrogen atmosphere. The reaction mixture was stirred at room temperature for 2.5 hours. Borane tetrahydrofuran (3 mL, 3 mmol) was added dropwise and the mixture was stirred at room temperature overnight. The resulting mixture was quenched cautiously by the addition of water (50 mL) and the mixture was concentrated under reduced pressure. The residue was diluted with water (30 mL) and extracted with EtOAc (2×200 mL), using brine to aid the separation. The combined organic extracts were washed with brine, dried over MgSO4, filtered and the solvent was removed under reduced pressure. The crude material was adsorbed onto silica and purification by chromatography eluting with 0-10% EtOAc in iso-hexane afforded the title compound.

1. stirringthe mixture was stirred at room temperature overnight
2. customThe resulting mixture was quenched cautiously by the addition of water (50 mL)
3. concentrationthe mixture was concentrated under reduced pressure
4. additionThe residue was diluted with water (30 mL)
5. extractionextracted with EtOAc (2×200 mL)
6. customthe separation
7. washThe combined organic extracts were washed with brine
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. customthe solvent was removed under reduced pressure
11. customThe crude material was adsorbed onto silica and purification by chromatography
12. washeluting with 0-10% EtOAc in iso-hexane

ORD record

ord-cbbbb022f11344a1946a326c0ff9f7f5

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403810B2