Nomenclature
CAS number: 126-81-8
1,1-Dimethyl-3,5-diketocyclohexane; 1,1-dimethyl-3,5-cyclohexanedione; dimethyldihydroresorcinol; dimedone; methone.
C
8H
12O
2; mol wt 140.18.
C 68.54%, H 8.63%, O 22.83%.
Description and references
Prepd from mesityl oxide and diethyl malonate:
Shriner, Todd, Org. Synth. coll. vol. II, 200 (1943).
Properties
Needles from water, prisms from alcohol + ether.
Dec 148-150°. Slightly volatile with steam (50 ml of a distillate
contained 0.016 g). The dry crystals may be stored in a brown bottle
for several years at room temp. Aq solns oxidize on exposure to air
and light or upon prolonged storage in the dark. 100 ml of a satd
aq soln contains 0.401 g at 19°; 0.416 g at 25°; 1.185 g at 50°; 3.020
g at 80°; 3.837 g at 90°. Monobasic acid in water. pK (25°): 5.15. Dipole moment
3.46. Also sol in methanol, ethanol, chloroform, benzene, acetic
acid, and in 50% ethanol-water mixture.Use
For the separation and identification of aldehydes.
Gives insol condensation products with aldehydes, but not with ketones.
The use of piperidine as a catalyst is recommended.