4.3 Alcohols And Phenols Flashcards
Halogenoalkane to alcohol
Reagents - aqueous NaOH
Conditions - heat under reflux
Reaction type - nucleophilic substitution
Aldehyde to primary alcohol
Sodium tetrahydridoborate dissolved in water with methanol
Reduction
Ketones to secondary alcohols
Sodium tetrahydridoborate dissolved in water with methanol
Reduction
Carboxylic acid to primary alcohol
Lithium tetrahydridoborate in ethoxyethene
Chlorination of alcohol
• pass HCl gas into the alcohol using anhydrous zinc chloride as a catalyst
• could also use phosphorous (V) chloride, sulfur dichloride oxide as chloride source
• SOCl2 has gaseous co-products are lost from the reaction mixture easily
Bromination of alcohol
• heat a mixture of the alcohol, potassium bromide and 50% sulfuric acid (catalyst)
Iodination of alcohol
• warm alcohol with a mixture of warm, damp red phosphorus and iodine
Alcohol and carboxylic acid
Forms ester and water
Conc sulphuric acid (catalyst)
Heat under reflux
Addition-elimination
Alcohols and ethanoyl chloride
Forms ester and HCl
Addition-elimination
Rapid
Which has higher yield between carboxylic acid and alcohol and ethanoyl chloride and alcohol
Ethanoyl chloride
Which is more cost effective as an industrial method between alcohols and carboxylic acid and alcohols and ethanoyl chloride
Carboxylic acid and alcohol
Acidity of phenol
Weakly acidic
Presence of the benzene ring weakens the O-H bond and so in aqueous solution protons are lost as the lone pair of electrons on the oxygen overlap with the pi electron system of the ring which causes the hydrogen ion to be lost more easily to form a phenoxide ion
Phenol with bromine water
Forms 2,4,6-tribromophenol which is an immediate white precipitate
The orange bromine water is decolourised
Phenol with ethanoyl chloride
Forms aromatic ester and HCl
Addition-elimination reaction
FeCl3 (aq) test for phenols
Yellow iron (III) chloride solution gives a purple/violet solution
