A process 2 wherein said ring closure is conducted using p toluenesulfonic acid or an ester or {TAIL ~ p toluenesulfonyl halide} with {HEAD ~ a tertiary amine} 
A process 2 wherein said ring closure is conducted using p toluenesulfonic acid or an ester or { TAIL ~ p toluenesulfonyl halide } with { HEAD ~ a tertiary amine }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD