The phosphatidylcholine biosynthetic process that begins with an initial N-methylation with phospho-base phosphoethanolamine, followed by two downstream N-methylations on phosphatidyl-bases, phosphatidyl-N-methylethanolamine and phosphatidyl-N-dimethylethanolamine. The process ends with the conversion of a phosphatidyl-N-dimethylethanolamine to a phosphatidylcholine.