amines and amides

• amines

  • are organic compounds in which one or more H in ammonia, NH3 is replaced with alkyl or aromatic groups

  
• common names of amines

  • simple amines are names as alkylamines
  • alkyl group bonded to N are listed in alphabetical order in front of amine

  
• IUPAC names of amines

  • named as an alkanamines
  • alkyl group bonded to N atom are listed in alphabetical order
• naming secondary and tertiary amines

  each alkyl group bonded to N is named N-alkyl

  
• aromatic amines

  amine of benzene = aniline

  
• hydrogen bonding for amines

  • polar N-H bond provides hydrogen bonding in primary and secondary amines but not tertiary
  • N-H bonds in amines are not as polar as O-H bonds in alcohol
• solubility in water

  • amines with 1-5 carbon atoms are soluble in water
  • N in amines forms hydrogen bonds with polar O-H bond in water
• amines react as...

  • bases
  • like ammonia, amines are weak bases in water

  
• neutralisation form amine salts

  • forms when amine neutralised by acid
  • named by replacing amine part with ammonium then name of negative ion

  eg.

  methylamine -----> methylammonium chloride
• properties of amine salts

  • solids at room temp
  • soluble in water and body fluids
  • the form used for drugs
• cocaine

  • sold illegally as an amine salt
  • cocaine reacted with NaOH to produce the free amine form known as crack
• heterocyclic amines

  • a five or six atom ring contains one or more nitrogen atoms
• alkaloids

  • physiologically active nitrogen-containing compounds
  • produced by plants
  • used as stimulants, anaesthetics and antidepressants
  • often habit forming
• caffeine

  • stimulant of the CNS
  • found in coffee beans, tea, chocolate and soft drinks
  • contains an imidazole ring
• nicotine

  • increases the adrenaline level in the blood
  • causes addiction to tobacco
  • contains pyrrolidine ring
• alkaloids related to morphine

  • eg. morphine and codeine have been used as painkillers
  • for centuries, morphine and codeine have been used a painkillers
  • heroin is a modification of morphine
• pharmacology

  • area of research is to design drugs with some characteristics of alkaloids
  • structures of cocaine and morphine are modified to produce anaesthesia but without the addictive side effects
  • parts of morphine structure that produce anaesthesia are found in procaine, lidocaine and demerol
• amides

  • in amides an amino group replaces the -OH group of carboxylic acids

  
• preparation of amides

  • produced by reacting a carboxylic acid with ammonia or amine

  
• naming amides

  • named as alkanamides
  • the -oic acid is replaced with -amide

  
• aromatic amides

  • amide of benzene is benzamide

  
• amides in health and medicine

  • urea is the end product of protein metabolism
  • saccharin is an artificial sweetener
  • some amides such as phenobarbital, Nembutal and Seconal are barbiturates (slows down brain and nervous system)
  • acetaminophen is used to reduce fever and pain
• physical properties of amides

  • hydrogen bonds form in primary and secondary, not tertiary amides
  • melting point of primary amides are higher than secondary amides which is higher than tertiary amides
  • all amides form hydrogen bonds with water
  • amides with 1-5 carbon atoms are soluble in water
• reactions of amides

  • acid hydrolysis to produce carboxylic acid and ammonium salt
  • base hydrolysis to produce salt of a carboxylic acid and an amine or ammonia