1,3-Cyclohexadiene → HCID 20035402, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 10.5 g (0.05 mol) of ethyl 6-isopropyl-2-methyl-3-cyclohexene-1-carboxylate (mixture of isomers obtained according to Example 1) and 9.8 g (0.055 mol) of N-bromosuccinimide dissolved in 75 ml of CCl4 was stirred for 3 hours under reflux. After cooling the reaction mixture was filtered and the filter cake was washed with some cold CCl4. The filtrate was evaporated down and the evaporation residue dissolved in 50 ml of dimethylformamide. 1.2 g of LiF and 3.4 g of Li2CO3 were added to this solution and the mixture was heated at 120° C. with continuous stirring for 1 hour. After cooling, 150 ml of water were added and the mixture was extracted 3 times with 50 ml of petroleum ether 40`-60. The extract was washed with water, dried and evaporated down, after which the residue was distilled. 8.1 g were obtained of a mixture, 60% of which consisted of the 2,4-cyclohexadiene isomer and the rest of the 1,3- and 2(exocyclic), 3-isomers of said compound. b.p.: 85°-88° C./0.6 kPa; NMR (data of the 2,4-isomer): 0.87 (3H, d, J=7 Hz); 0.90 (3H, d, J=7 Hz); 1.24 (3H, t, J=7 Hz); 1.6 (1H, m); 1.77 (3H, broad s); 2.54 (1H, m); 2.86 (1H, d, J=7 Hz); 4.07 (2H, k, J=7 Hz); 5.3-5.9 (3H).

Provenance & Evidence