Synthesis of Cyclohexanone from Cyclohexanol by Oxidation

Synthesis of Cyclohexanone from Cyclohexanol by Oxidation

Miaya Conyers

Organic Chemistry Lab 145-05

2017 March 2

Abstract

The objective of this experiment was to produce cyclohexanone from the oxidation of cyclohexanol with the presence of sodium dichromate in sulfuric acid. Using sodium dichromate in sulfuric acid as a catalyst, the purpose of this lab was to produce a ketone through an oxidation reaction to form an alcohol. Infrared spectroscopy was analyzed to identify the strong carbonyl stretch group with peak at 1750 and 2929.53 cm-1. Functional O-H group was observed at 3400-3200 cm-1. The lack of peaks at other ranges suggested that the product was a ketone. To determine the product, simple distillation was performed followed by IR results to identify the purity of the product. Cyclohexene was synthesized from cyclohexanol by dehydration in the presence of a strong acid, in this case, phosphoric acid. The cyclohexene product was isolated from cyclohexanol through distillation, and then further isolated from water by pipetting and the use of drying salts. The observed melting point was -31.2°C. The percent yield of cyclohexene obtained was 68.104%, which is lower than the expected percent yield of 80%. This is assumed to be due to errors while carrying out this experiment.

Introduction

In this experiment, alcohols was converted into carbonyl group through oxidation. Oxidation reaction is the loss of an electron or an increase in oxidation state. It always occurs with reduction reaction, which is the gain of an electron. Cyclohexanol is the reductant and the product of bleach reacted with acetic acid, HOCl, is the active oxidant. The product of the reaction is cyclohexanone. The product will be isolated by simple distillation and analyzed through gas chromatography and IR[1].

Balanced equation*

Cyclohexanol

Melting Point: 25°C

Boiling Point: 161°C

Density: 0.96 g/mL

Molecular Weight: 100.16 g/mol

Cyclohexanone

Melting Point: -31.2°C

Boiling Point: 156°C

Density: 0.95 g/mL

Molecular Weight: 98.14 g/mol

Calculations

6g cyclohexanol/100.16g/mol = 0.060 mol (limiting reagent)

0.060 mol * 98.14g/1 mol = 5.88 g (product-cyclohexanone)

Actual/Theoretical * 100 = Percent yield

Theoretical yield: 0.041 mol

Percent yield: 68.104%

Observed melting point = -31.2°C

Colorless liquid

Experimental

First, transfer 6g of cyclohexanol to a