Reaktion #44020

Reaktionsgleichung

compound 104

ethyl 1-(4-chlorophenylsulfonyl)-3-((dimethylamino)methylene)-4-oxo-1,2,3,4-tetrahydropyridine-2-carboxylate

acetic acid

Hydrazine hydrate

→

compound 105

Ausbeute 30.4%

ethyl 5-(4-chlorophenylsulfonyl)-4,5-dihydro-1H-pyrazolo[4,3-c]pyridine-4-carboxylate

Ausbeute 30.4%

Lösungsmittel

EtOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction mixture was concentrated in vacuo
2. 2
   WaschenThe organic layer was washed with sat. aq. NaHCO3, brine
3. 3
   Trocknendried over Na2SO4
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo
6. 6
   Sonstigeto yield crude material that
7. 7
   Sonstigewas purified by flash chromatography (50% EtOAc/hexanes)

Vorschrift

A flask was charged with compound 104 (5.8 g, 14.6 mmol), acetic acid (10 mL) and EtOH (10 mL). Hydrazine hydrate (1.4 mL, 30 mmol) was added and the reaction stirred at room temperature for 2 hours. The reaction mixture was concentrated in vacuo and the residue was taken up in EtOAc. The organic layer was washed with sat. aq. NaHCO3, brine, dried over Na2SO4, filtered, and concentrated in vacuo to yield crude material that was purified by flash chromatography (50% EtOAc/hexanes) to yield 1.63 g (30%) of compound 105 as a yellow foam. 1H NMR (CDCl3) δ 7.76 (d, J=6.3 Hz, 2H), 7.48-7.41 (m, 3H), 6.90-6.87 (m, 1H), 5.96-5.93 (m, 1H), 5.80 (s, 1H), 4.13-4.11 (m, 2H), 1.24-1.18 (m, 3H; MS (m/z) 368.0 (M+H)+.

Quelle