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