Reaktion #500241

Reaktionsgleichung

ethyl 8,9-difluoro-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate

2-(3,4-dimethylphenyl)piperazine

water

→

ethyl 9-[3-(3,4-dimethylphenyl)piperazin-1-yl]-8-fluoro-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate

Ausbeute 42.0%

Lösungsmittel

dimethyl sulphoxide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtrationfiltered
2. 2
   SonstigeThe residue obtained
3. 3
   Sonstigewas chromatographed on a Merck silica gel column (particle size 0.04-0.06 mm, diameter 5.5 cm, height 45 cm)
4. 4
   Wascheneluted at an argon pressure of 120 kPa with a mixture of dichloromethane and ethanol (92/8 mixture by volume) and 50 cm3 fractions
5. 5
   Sonstigewere collected
6. 6
   Einengenconcentrated to dryness under reduced pressure (2.7 kPa)

Vorschrift

A stirred suspension of 2.5 g of ethyl 8,9-difluoro-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate and 2.6 g of 2-(3,4-dimethylphenyl)piperazine in 45 cm3 of dimethyl sulphoxide was heated at a temperature in the region of 100° C. for about 100 hours. The reaction mixture was treated with 400 cm3 of water and filtered. The residue obtained was chromatographed on a Merck silica gel column (particle size 0.04-0.06 mm, diameter 5.5 cm, height 45 cm), eluted at an argon pressure of 120 kPa with a mixture of dichloromethane and ethanol (92/8 mixture by volume) and 50 cm3 fractions were collected. Fractions 37 to 80 were combined and then concentrated to dryness under reduced pressure (2.7 kPa). 1.61 g of ethyl 9-[3-(3,4-dimethylphenyl)piperazin-1-yl]-8-fluoro-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate was obtained in the form of a yellow solid, which melted at 290° C.

Quelle