Methylation of {HEAD ~ compound} 3 with {TAIL ~ iodomethane} in the presence of a base, such as sodium hydride, provides N methylated product of structure 5 
with
Methylation of { HEAD ~ compound } 3 with { TAIL ~ iodomethane } in the presence of a base , such as sodium hydride , provides N methylated product of structure 5
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH