Ethyl 1,4-dibenzylpiperazine-2-carboxylate → (1,4-Dibenzylpiperazin-2-yl)methanol

Temperature

0 °C

To a stirred solution of lithium aluminium hydride in THF (1 M, 49.6 mL, 49.6 mmol) at −5° C. under nitrogen was added, dropwise over 0.5 h, a solution of (1,4-dibenzyl-piperazin-2-yl)-carboxylic acid, ethyl ester (8.4 g, 24.8 mmol) in THF (30 mL), internal temperature kept <5° C. Resulting mixture was stirred at 0° C. for 1 h then at 20° C. for 18 h, then was quenched by addition of a mixture of water (4 mL) and THF (100 mL) with external cooling in an ice-methanol bath. The resulting suspension was treated with saturated aqueous potassium sodium tartrate (−50 mL) and mixture was allowed to stir at 0° C. for 1 h. The supernatant liquid was decanted and evaporated in vacuo. The resulting oil was dissolved in dichloromethane and the solution dried (Na2SO4) and evaporated in vacuo to give the title compound (8.04 g) as an oil. MS: [M+H]+=297.

1. customkept <5° C
2. customResulting mixture
3. waitat 20° C. for 18 h
4. customwas quenched by addition of a mixture of water (4 mL) and THF (100 mL)
5. temperaturewith external cooling in an ice-methanol bath
6. additionThe resulting suspension was treated with saturated aqueous potassium sodium tartrate (−50 mL) and mixture
7. stirringto stir at 0° C. for 1 h
8. customThe supernatant liquid was decanted
9. customevaporated in vacuo
10. dissolutionThe resulting oil was dissolved in dichloromethane
11. dry with materialthe solution dried (Na2SO4)
12. customevaporated in vacuo

ORD record

ord-bc090474746544419ac5d275fd70b179

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09018214B2