Reaktion #162353

Reaktionsgleichung

1,2-diethyl 4-cyanotetrahydro-1,2-pyridazinedicarboxylate

product

1,2-diethyl 4-cyanotetrahydro-1,2-pyridazinedicarboxylate

thioacetamide

→

title compound

1,2-diethyl 4-(aminothioxomethyl)tetrahydro-1,2-pyridazinedicarboxylate

Lösungsmittel

trifluoroacetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was cooled
2. 2
   Sonstigepartitioned between water and diethyl ether (about 30 mL)
3. 3
   SonstigeThe layers were separated
4. 4
   Extraktionthe aqueous layer was extracted with diethyl ether (2×)
5. 5
   WaschenThe combined organic extracts were washed with water (about 30 mL), dried magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated
8. 8
   Sonstigepurified by silica gel column chromatography (25% to 60% gradient of ethyl acetate in petroleum ether as eluant)

Vorschrift

A mixture of 1,2-diethyl 4-cyanotetrahydro-1,2-pyridazinedicarboxylate (i.e the product of Step E) (5.5 g, 0.024 mol) and thioacetamide (5.5 g, 0.073 mol) in trifluoroacetic acid (about 10 mL) was heated at 50° C. for 20 h. The reaction mixture was cooled, and then partitioned between water and diethyl ether (about 30 mL). The layers were separated and the aqueous layer was extracted with diethyl ether (2×). The combined organic extracts were washed with water (about 30 mL), dried magnesium sulfate, filtered and concentrated under reduce pressure to an orange oil. The oil was adsorbed onto Celite® (diatomaceous filter aid), and then purified by silica gel column chromatography (25% to 60% gradient of ethyl acetate in petroleum ether as eluant) to provide the title compound as a yellow solid (3.97 g).

Quelle