tert-Butyl carbamate → tert-butyl N-(5-chloropyridazin-3-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

**_April 15 2016_** 3,5-dichloropyridazine (1 g, 6.71 mmol), tert-butyl carbamate (3.93 g, 33.56 mmol), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane) (0.583 g, 1.01 mmol), PdOAc2 (0.452 g, 2.01 mmol) and CS2CO3 (4.37 g, 13.43 mmol) in 1,4-dioxane (20 mL) was degassed through recharged with nitrogen, and was heated at 80 °C overnight. **_April 18 2016_** LCMS showed 23% of the precursor @ 0.55 min (no mass ionization) left on a 2-min basic run. GCMS showed no precursor and 94% of an unknown @ 6.90 min (whihc might be the desired product but not ionizable) on a 10-min run. The reaction was cooled to RT. The crude mixture was concentrated to givr a dark-brown gum. The dark-brown gum was dissolved in EtOAc, washed with water, and evaporated to give a brown solid. The brown solid was passed through a 10 g SiO2 flash column eluting with EtOAc, collected all of the eluent, and then evaporated to give a brown solid as the crude. The crude would be used in EN08121-59 without purification, assuming 100% yield.

Provenance & Evidence