What is formed when benzoyl chloride reacts with aniline in the presence of sodium hydroxide 

It is known as Schotten Baumann reaction. 

$\underset{\text{ Aniline }}{{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}_2}+\underset{\text{ Benseylthibrice }}{{\mathrm{ClCOC}}_6{\mathrm{H}}_5}\stackrel{\mathrm{NaOH}}{\to }{\mathrm{C}}_6\underset{ }{{\mathrm{H}}_5\mathrm{NH}-{\mathrm{COC}}_6{\mathrm{H}}_5+\mathrm{NaCl}+{\mathrm{H}}_2\mathrm{O}}$

                                                        Benzanilide