Citric Acid → HCID 21193269, Verbindung

To a 0° C. suspension of sodium hydride (19 mg, 0.80 mmol) in 1.5 ml of THF, was added a solution of N-t-butoxycarbonyl-4-hydroxymethyl-4-(2-methylbenzyl)piperidine (200 mg, 0.63 mmol) in 1 ml THF. The mixture was allowed to warm to room temp. To this suspension was added 0.35 ml of anhydrous DMSO and the mixture was heated to 60° C. and stirred 5 h until the solution was almost homogeneous. The reaction mixture was allowed to cool to room temp. and to this solution was added methyl iodide (0.070 ml, 1.12 mmol). The resulting heterogeneous mixture was stirred at room temp. overnight. The reaction mixture was treated with 10% aqueous citric acid and extracted with ether (3×). The combined ether extracts were washed successively with saturated aqueous NaHCO3 and brine, dried (MgSO4), and concentrated in vacuo to a yellow gum. Purification by column chromatography on silica with 9% EtOAc/hexane as eluent afforded the product as a colorless gum.

1. temperaturethe mixture was heated to 60° C.
2. temperatureto cool to room temp. and to this solution
3. stirringThe resulting heterogeneous mixture was stirred at room temp. overnight
4. extractionextracted with ether (3×)
5. washThe combined ether extracts were washed successively with saturated aqueous NaHCO3 and brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo to a yellow gum
8. customPurification by column chromatography on silica with 9% EtOAc/hexane as eluent

ORD-Eintrag

ord-8240e3c4982e494a823b484956307435

Quelldatensatz

uspto-grants-1996_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05576313