Reaktion #71632

Reaktionsgleichung

D43

1,1-Dimethylethyl (2R,6S)-4-[(4-bromophenyl)methyl]-2,6-dimethyl-1-piperazinecarboxylate

methyl 2-methylpropanoate

lithium dicyclohexylamide

→

title compound

Ausbeute 65.5%

1,1-Dimethylethyl (2R,6S)-4-({4-[1,1-dimethyl-2-(methyloxy)-2-oxoethyl]phenyl}methyl)-2,6-dimethyl-1-piperazinecarboxylate

Ausbeute 65.5%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe reaction mixture stirred at room temperature overnight
2. 2
   SonstigeThe solvent was removed in vacuo and chromatography
3. 3
   Wascheneluting with 0-90% EtOAc/petroleum ether

Vorschrift

A solution of methyl 2-methylpropanoate (188 ul, 1.64 mmol) in toluene (3 ml) was added to lithium dicyclohexylamide (362 mg, 1.93 mmol) under glove bag conditions. The suspension was stirred for 10 mins then added to a mixture of D43 (570 mg, 1.49 mmol) and bis(dibenzylideneacetone) palladium (0) (43 mg, 0.074 mmol). Tri(tert-butyl)phosphine (18 ul, 0.074 mmol) was added and the reaction mixture stirred at room temperature overnight. The solvent was removed in vacuo and chromatography eluting with 0-90% EtOAc/petroleum ether gave the title compound as a yellow oil (395 mg). δH (CDCl3, 250 MHz) 7.29 (4H, m), 4.07 (2H, m), 3.66 (3H, s), 3.46 (2H, s), 2.61 (2H, m), 2.12 (2H, dd), 1.58 (6H, s), 1.46 (9H, s), 1.29 (6H, d). MS (ES): MH+ 405.

Quelle