Reaction #2460286

Reaction equation

2-butynedioic acid

n-butyl alcohol

sulfuric acid

→

dibutyl acetylenedicarboxylate

Conditions

Workup

1. 1
   Temperaturewas heated
2. 2
   Temperatureat reflux for 6 hours
3. 3
   TemperatureThe mixture was cooled to ambient,
4. 4
   Washwashed with 10% aqueous NaHCO3
5. 5
   Dryingwith brine, dried (Na2SO4)
6. 6
   Concentrationconcentrated
7. 7
   workup.DISTILLATIONthe resulting crude product distilled under reduced pressure (bp 65-70° C./0.08 mm)
8. 8
   OtherDibutyl acetylenedicarboxylate was obtained as a colorless oil (8.5 g, 86% of theory)

Procedure

First, dibutyl acetylenedicarboxylate was prepared. A mixture of 2-butynedioic acid (5.0 g, 44 mmol), n-butyl alcohol (162 g, 2.19 mol), and sulfuric acid (0.86 g, 9 mmol) was heated at reflux for 6 hours. The mixture was cooled to ambient, washed with 10% aqueous NaHCO3 then with brine, dried (Na2SO4), concentrated, and the resulting crude product distilled under reduced pressure (bp 65-70° C./0.08 mm). Dibutyl acetylenedicarboxylate was obtained as a colorless oil (8.5 g, 86% of theory). 1H NMR (CDCl3): δ 1.90 (t, 6H), 1.38 (m, 4H), 1.65 (m, 4H), 4.20 (t, 4H).

Source