Lithium borohydride → β-Amino-β-butylbenzenepropanol

To a solution of methyl ester (0.13 g, 0.55 mmol) from step B in 7.8 mL THF was added LiBH4 (2.3 mL, 4.6 mmol, 2M in THF). After 2 h at reflux, the reaction was cooled to rt and quenched by the dropwise addition of MeOH, followed by acetone. After the volatiles were removed in vacuo, the remaining residue was redissolved in 23 mL 1N HCl and heated to 45° C. for 1.5 h. The volatiles were removed in vacuo, and the remaining residue was redissolved in saturated aqueous NaHCO3. The aqueous layer was extracted with CHCl3 (4×), the combined organics layers were dried over Na2SO4, filtered and concentrated to afford 2-amino-2-benzylhexan-1-ol II which was used for the next reaction without further purification. 1H NMR (400 MHz, CDCl3) δ 7.32-7.18 (m, 5H), 3.32 (m, 2H), 7.70 (m, 2H), 1.53-1.31 (m, 6H), 0.93 (t, J=6.8 Hz, 3H) LCMS M+H=208.

1. temperatureAfter 2 h at reflux
2. customquenched by the dropwise addition of MeOH
3. customAfter the volatiles were removed in vacuo
4. dissolutionthe remaining residue was redissolved in 23 mL 1N HCl
5. temperatureheated to 45° C. for 1.5 h
6. customThe volatiles were removed in vacuo
7. dissolutionthe remaining residue was redissolved in saturated aqueous NaHCO3
8. extractionThe aqueous layer was extracted with CHCl3 (4×)
9. dry with materialthe combined organics layers were dried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated

ORD record

ord-625ec1194d0549cea460e3ee4625f9c4

Source dataset

uspto-grants-2008_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07354942B2