Reaction #1571

Reaction equation

1,4-Dibromobutane

1,2-dicarbethoxyhydrazine

potassium carbonate

→

title product

Yield 69.4%

Tetrahydro-1,2-pyridazinedicarboxylic acid, diethyl ester

Yield 69.4%

Solvents

acetonitrile

Conditions

Workup

1. 1
   OtherThe resultant reaction mixture
2. 2
   Temperatureis refluxed for 6 hours
3. 3
   Filtrationfiltered
4. 4
   ConcentrationThe filtrate is concentrated in vacuo
5. 5
   Otherto obtain a yellow liquid which
6. 6
   workup.DISTILLATIONis distilled under reduced pressure

Procedure

1,4-Dibromobutane (81.4 mL, 0.682 mol) is added over 1 hour to a mixture of 1,2-dicarbethoxyhydrazine (100 g, 0.568 mol) and potassium carbonate (158 g, 1.14 mol) in acetonitrile (600 mL). The resultant reaction mixture is refluxed for 6 hours, cooled to room temperature, and filtered. The filtrate is concentrated in vacuo to obtain a yellow liquid which is distilled under reduced pressure to give the title product as a colorless liquid (90.8 g, bp 115°-120° C. at 0.9 mm Hg).

Source