R−CONH2\mathrm{R}-\mathrm{CONH}_{2}R−CONH2
R−NH2\mathrm{R}-\mathrm{NH}_{2}R−NH2
R−COCl\mathrm{R}-\mathrm{COCl}R−COCl
R−COBr\mathrm{R}-\mathrm{COBr}R−COBr
