Reaction #43448

Reaction equation

2-[(3,6-dichloro-4-pyridazinyl)oxy]ethanol

lithium hydride

→

3-Chloro-6,7-dihydro[1,4]dioxino[2,3-c]pyridazine

Solvents

1,4-dioxane

Conditions

Workup

1. 1
   Temperatureheated at 110° C. overnight
2. 2
   OtherThe reaction mixture was quenched with wet 1,4-dioxane
3. 3
   OtherThe solution was evaporated to half volume
4. 4
   Otherevaporated to dryness
5. 5
   workup.ADDITIONWater was added
6. 6
   Extractionthe residue was extracted 5× with chloroform
7. 7
   Dryingdried (sodium sulphate)
8. 8
   Otherevaporated
9. 9
   Otherto afford

Procedure

A solution of 2-[(3,6-dichloro-4-pyridazinyl)oxy]ethanol containing some bromo-derivative (15.46 g; 0.0703 mol) in dry 1,4-dioxane (1.2 L) was treated with lithium hydride (2.3 g; 0.28 mol) in portions and stirred at room temperature for 1 hour under argon, then heated at 110° C. overnight. The reaction mixture was quenched with wet 1,4-dioxane, then iced-water. The solution was evaporated to half volume, taken to pH 8 with 5M hydrochloric acid and evaporated to dryness. Water was added and the residue was extracted 5× with chloroform, dried (sodium sulphate) and evaporated to afford a white solid (12.4 g, ca. 77%) (containing ca. 15% of a bromo species).

Source