Triethylamine → Ethyl 6-chloro-(1,2,4)triazolo(4,3-b)pyridazine-3-carboxylate

HRID 521576Notes

Reaction equation

HRID 521576 reaction equation
Br[C:2](=[N:8][NH:9][C:10]1[N:11]=[N:12][C:13]([Cl:16])=[CH:14][CH:15]=1)[C:3]([O:5][CH2:6][CH3:7])=[O:4].C(N(CC)CC)C>C(O)(C)C>[Cl:16][C:13]1[CH:14]=[CH:15][C:10]2[N:11]([C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])=[N:8][N:9]=2)[N:12]=1

Participants

4

Reactant 2

HCID 8471TriethylamineHCID 89287509Ethyl 2-bromo-2-(2-(6-chloropyridazin-3-yl)hydrazono)acetate

Product 1

HCID 11287584Ethyl 6-chloro-(1,2,4)triazolo(4,3-b)pyridazine-3-carboxylateYield 88.3%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

A mixture of compound ethyl 2-bromo-2-(2-(6-chloropyridazin-3-yl)hydrazono)acetate (1.25 g, 4 mmol) in 10 mL of isopropanol with 0.5 mL of triethylamine was refluxed for 1 h. The solution was evaporated and the residue was washed thoroughly with water to give product ethyl 6-chloro-[1,2,4]triazolo[4,3-b]pyridazine-3-carboxylate as a yellow solid (0.8 g, 67%). LRMS (M+H+) m/z: calcd 227.03; found 227. 1H NMR (300 MHz, CDCl3): δ 8.25-8.22 (d, J=9.6 Hz, 1H), 7.34-7.31 (d, J=9.6 Hz, 1H), 4.64-4.56 (q, 2H), 1.53-1.49 (t, 3H).

Workup

  1. temperaturewas refluxed for 1 h
  2. customThe solution was evaporated
  3. washthe residue was washed thoroughly with water

Sources & evidence

ORD record
ord-bc2f66d18ed143f5ac55493eb5b29e3a
Source dataset
uspto-grants-2016_05
Patent number
US09328117B2

Reaction notes

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