Borane → 5-Hydroxy-2-methylnorvaline

Temperature

0 °C

Finely ground racemic a-methylglutamic acid (5.0 g, 0.029 mol) was suspended in THF (30 mL), treated with triethylborane (1M in THF, 32.32 mL, 0.032 mol), and heated at reflux for 36 h. After cooling to 0° C. the soln was treated dropwise with borane in THF (1M, 35.26 mL, 0.035 mol) and stirred at 0° C. for 3 h. The mixture was quenched with 5% aq HCl (30 mL), stirred for 0.5 h, concentrated on a rotary evaporator, and the residue dissolved in 5% HCl (44 mL) and heated at reflux for 0.75 h. After cooling and concentrating, the residue was taken up in MeOH (50 mL), concentrated, and this procedure repeated 3×to give 5.69 g of the title compound which was not purified.

1. temperatureheated
2. temperatureat reflux for 36 h
3. customThe mixture was quenched with 5% aq HCl (30 mL)
4. stirringstirred for 0.5 h
5. concentrationconcentrated on a rotary evaporator
6. dissolutionthe residue dissolved in 5% HCl (44 mL)
7. temperatureheated
8. temperatureat reflux for 0.75 h
9. temperatureAfter cooling
10. concentrationconcentrating
11. concentrationconcentrated

ORD record

ord-8e5092d0c3724cb1b8b3f5749efcfa3a

Source dataset

uspto-grants-1994_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05326773