Preparation of Cyclohexanol
Introduction:
Cyclohexanol is mainly used in the production of caprolactam and adipic acid that is a raw material of nylon 6 (Zhang, et al, 2002). Cyclohexanol can be produce through several methods, which include the oxidation of cyclohexane, the hydration of cyclohexene, or the hydrogenation of phenol (Zhang, et al, 2002). Problem with oxidation of cyclohexene is poor selectivity, extremely large recycles and explosion hazards. (Suresh, Sridhar, Potter, 1988). The purpose of this experiment was to synthesis cyclohexanol by hydration of cyclohexene using concentrated sulphuric acid as an acidic catalyst. In hydration reaction, C=C B bond is replaced by hydroxyl group (Hornback, 2006).
Overall reaction: (McFadden, 2012)
In the first step, the mixture of water, concentrated sulphuric acid, and cyclohexene was shaken vigorously until it became a homogenous solution. Followed by, the addition of water, and the distillation process lead to the hydrolysis of the alkene. Finally, addition of diethyl ether to the mixture then distillation took place to be purified and to obtain the final product, cyclohexanol (McFadden, 2012). Diethyl ether was used to extract alcohol from salt-water mixture because diethyl ethers solubility in water is lower than cyclohexanol which helps remove alcohol from the salt-water mixture (Merzougui, A, et al., 2011). (McFadden, 2012)
Cyclohexene is added to water-acid solution, which formed two liquid phases were due to insolubility of cyclohexene in water-acid solution. It is very important that mixture is mixed well to make a homogeneous solution and allow reaction to complete. Cyclohexene was reacted with water and with sulfuric acid to form protonated cyclohexanol and cyclohexyl hydrogen sulfate. Protonated cyclohexanol and cyclohexyl hydrogen sulfate are soluble in water-acid solution (McFadden, 2012).
Cyclohexanol is mainly used in the production of caprolactam and adipic acid that is a raw material of nylon 6 (Zhang, et al, 2002). Cyclohexanol can be produce through several methods, which include the oxidation of cyclohexane, the hydration of cyclohexene, or the hydrogenation of phenol (Zhang, et al, 2002). Problem with oxidation of cyclohexene is poor selectivity, extremely large recycles and explosion hazards. (Suresh, Sridhar, Potter, 1988). The purpose of this experiment was to synthesis cyclohexanol by hydration of cyclohexene using concentrated sulphuric acid as an acidic catalyst. In hydration reaction, C=C B bond is replaced by hydroxyl group (Hornback, 2006).
Overall reaction: (McFadden, 2012)
In the first step, the mixture of water, concentrated sulphuric acid, and cyclohexene was shaken vigorously until it became a homogenous solution. Followed by, the addition of water, and the distillation process lead to the hydrolysis of the alkene. Finally, addition of diethyl ether to the mixture then distillation took place to be purified and to obtain the final product, cyclohexanol (McFadden, 2012). Diethyl ether was used to extract alcohol from salt-water mixture because diethyl ethers solubility in water is lower than cyclohexanol which helps remove alcohol from the salt-water mixture (Merzougui, A, et al., 2011). (McFadden, 2012)
Cyclohexene is added to water-acid solution, which formed two liquid phases were due to insolubility of cyclohexene in water-acid solution. It is very important that mixture is mixed well to make a homogeneous solution and allow reaction to complete. Cyclohexene was reacted with water and with sulfuric acid to form protonated cyclohexanol and cyclohexyl hydrogen sulfate. Protonated cyclohexanol and cyclohexyl hydrogen sulfate are soluble in water-acid solution (McFadden, 2012).