Triphosgene → HCID 59716808, compound

Participants

Reaction Steps

A stirring solution of triphosgene (19.0 g, 64.0 mmol) in THF (200 mL) was cooled to 0° C. under argon and the mixture of 1-(4-chloro-5-p-tolylpyridazin-3-yl)hydrazine and 1-(3-chloro-5-p-tolylpyridazin-4-yl)hydrazine (3.0 g gross), prepared as described in Example 362C, was added over 3 min. The reaction mixture was allowed to warm to RT gradually and then stirred for 16 h. Solvent was removed under vacuum to reduce the reaction mixture to half its original volume, and the resulting suspension was cooled to an ice bath. Ice water (300 mL) was added, followed by stirring for 1 h. The product was collected by filtration and washed with 0.1 M aqueous HCl (50 mL×2), then H2O (50 mL×2). After drying under vacuum at 50° C. for 2 d, the title compound, 8-chloro-7-p-tolyl-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one, (2.2 g) was obtained as a yellow solid. MS [M+H]+ 261; HPLC retention time=2.75 min; 1HNMR (400 MHz, THF-d8) δ 11.69 (s, 1H), 8.10 (s, 1H), 7.49-7.51 (m, 2H), 7.34-7.35 (m, 2H).

Provenance & Evidence