Reaktion #218297

Reaktionsgleichung

2,4-dichloro-pyrido[2,3-d]pyrimidine

phosphoric acid

2-aminonicotinic acid

N-t-butoxycarbonyl piperazine

Hunig's base

→

4-(2-Chloro-pyrido[2,3-d]pyrimidin-4-yl)-piperazine-1-carboxylic acid tert-butyl ester

Ausbeute 40.0%

Lösungsmittel

methanol

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe white solid was collected by filtration
2. 2
   Waschenwashed with water and cold ethanol
3. 3
   Sonstigedried
4. 4
   Sonstigeto afford C1.1 (105 mg, 40% yield)

Vorschrift

A mixture of 2,4-dichloro-pyrido[2,3-d]pyrimidine (150 mg, 0.75 mmol, 1 eq) [prepared from 2-aminonicotinic acid by the methods of Robins et al. (J. Am. Chem. Soc. 1955, 77, 1045.) and Oakes et al. (J. Chem. Soc. 1956, 1045.)], N-t-butoxycarbonyl piperazine (147 mg, 0.787 mmol, 1.05 eq) and Hunig's base (0.39 mL, 2.25 mmol, 3 eq) in ethanol (2.5 mL) was stirred at rt for 17 hr. The white solid was collected by filtration, washed with water and cold ethanol, and dried to afford C1.1 (105 mg, 40% yield). LC/MS: 350.41 [M+H]+; HPLC: >95% at 1.44 min (Xterra 5 μm C18 column 4.6×30 mm, 10-90% aqueous methanol over 2 min containing 0.2% phosphoric acid, 5 mL/min, monitoring at 254 nm).

Quelle