A process for liquefying natural gas containing mercaptans. Mercaptans are concentrated into a distillate stream by distilling the feed gas stream without specific pretreatment for mercaptans removal. Thus, the mercaptans removal equipment is much smaller since mercaptans treatment can take place at a point in the process where the flowrate is much lower. A portion of the treated distillate stream can be reinjected to the upstream distilling stage to facilitate mercaptan absorption.