Reaktion #1517257

Reaktionsgleichung

ammonium chloride

n-butyllithium

2-bromo-4-chloropyridine

tert-butyl 4-oxopiperidine-1-carboxylate

→

tert-butyl 4-(4-chloropyridin-2-yl)-4-hydroxypiperidine-1-carboxylate

Lösungsmittel

CH2Cl2

CH2Cl2

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITAfter 1 h
2. 2
   Waschenwashed with saturated aqueous sodium bicarbonate and brine
3. 3
   TrocknenThe organic solution was dried over sodium sulfate
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo
6. 6
   SonstigeThe resultant residue was purified via silica gel chromatography
7. 7
   Wascheneluting with 0-20% ethyl acetate in hexanes

Vorschrift

To a solution of 2-bromo-4-chloropyridine (C2) (1.00 g, 5.20 mmol) in CH2Cl2 (10 mL) cooled to −78° C. was added n-butyllithium (1.6 M in hexanes, 3.57 mL, 5.72 mmol) dropwise. After 15 min, a solution of tert-butyl 4-oxopiperidine-1-carboxylate (C1) (1.14 g, 5.72 mmol) in CH2Cl2 (3 mL) was added dropwise. After 1 h, saturated aqueous ammonium chloride (5 mL) was added. The mixture was warmed to ambient temperature, diluted with CH2Cl2 and washed with saturated aqueous sodium bicarbonate and brine. The organic solution was dried over sodium sulfate, filtered, and concentrated in vacuo. The resultant residue was purified via silica gel chromatography eluting with 0-20% ethyl acetate in hexanes to provide tert-butyl 4-(4-chloropyridin-2-yl)-4-hydroxypiperidine-1-carboxylate (C3).

Quelle