Dehydrogenation of 1,4-Butanediol (1,4-BD) to gamma-Butyrolactone (GBL)
A mixture of 90.1g (1 mole) 1,4-butanediol, 4g of copper chromite catalyst and 0.15g of powdered reagent grade sodium hydroxide (or better KOH) was stirred vigorously and heated under reflux. At about 200°C, a lively evolution of hydrogen occurred, and the temperature dropped about 10°C and the dehydrogenation proceeded smoothly. The evolution of gas (39L/2mol per mole 1,4-butanediol reacted) ceased in about 3h. The reaction mixture was cooled to room temperature, filtered from the catalyst and distilled under reduced pressure to give gamma-butyrolactone in about 80% yield and unreacted 1,4-butanediol in about 10% yield.
Other references for the transformation of 1,4-Butanediol to gamma-Butyrolactone
References
[1] JACS 68, 1385 (1946)
