Addition reactions to give haloalkanes
The reaction of an alkane to form a haloalkane (alkyl (An alkane minus one hydrogen atom. Examples: CH3 (methyl) and CH3CH2 (ethyl). Alkyl groups are often represented by R when showing general formulae such as RCO2H or RX (X = Cl,Br).) halide) is unusual in that reaction can, in principle, occur at any carbon. Most reactions of organic molecules result in change at particular carbons(s) which are in the part of the molecule known as the functional group, and no change occurs at other carbons.
Classifying organic reactions highlights similarities between reactions that may at first appear different. This makes learning reaction chemistry easier. The two classifications below are based on differences in the structure of the organic product and the organic reactant.
Classifying organic reactions highlights similarities between reactions that may at first appear different. This makes learning reaction chemistry easier. The two classifications below are based on differences in the structure of the organic product and the organic reactant.
A part of the organic molecule is exchanged with a part of the reagent (One of the reactants in a reaction. In organic chemistry the reagent is the nonorganic reactant.).
Two parts of a reagent molecule are added across an unsaturation (Unsaturated compounds contain a multiple (double or triple) bond.) to give an organic product that has one less unsaturation than the organic reactant.
Reaction of alkenes with halogens (X2) or HX is a more useful way to prepare haloalkanes as reaction occurs specifically at the doubly bonded carbons.
Reaction of a halogen with an alkane is an example of a substitution reaction at saturated carbon.
CH3–CH2–H + Cl–Cl 
CH3CH2–Cl + H–Cl
CH3CH2–Cl + H–Cl Two parts of a reagent molecule are added across an unsaturation (Unsaturated compounds contain a multiple (double or triple) bond.) to give an organic product that has one less unsaturation than the organic reactant.
CH2=CH2 + Br–Br → Br–CH2–CH2–Br
CH2=CH2 + H–Cl → H–CH2–CH2–Cl
CH2=CH2 + H–Cl → H–CH2–CH2–Cl
Reaction of alkenes with halogens (X2) or HX is a more useful way to prepare haloalkanes as reaction occurs specifically at the doubly bonded carbons.
substitution
addition
addition