Structure and anticholinesterase activity of series of ethyl substituted phenyl methylphosphonates.

Thirty derivates from substituted-phenyl-ethyl methylphosphonates have been synthesized and their inhibiting power of acetyl-cholinesterase have been examined in vitro and in vivo. The correlation between inhibition of the enzyme and electrophylic power of the substituent of the phenyl group was excellent, but when this group contains two substituents, steric factors appear to operate. The activity of these compounds has been demonstrated to be higher than their phosphate analogs.