Abstract: The present invention provides novel 19,20-didehydro-PG.sub.1 amides methods for their preparation and pharmacological use for the induction of prostaglandin-like effect.

Abstract: A herbicidal composition which comprises as an active ingredient a m-phenoxybenzamide compound of the formula: ##STR1## wherein X, which may be the same or different, is a halogen atom or a lower alkyl or lower alkoxy group, n is zero or an integer of 1 to 5 and R is a group of the formula: ##STR2## (in which R.sub.1 is a hydrogen atom or a lower alkyl or lower alkenyl group and R.sub.2 is a lower alkyl, lower alkenyl, lower alkynyl, lower alkoxy, lower cycloalkyl, lower haloalkyl, lower alkoxy-substituted lower alkyl, lower cyanoalkyl, lower alkylamino-substituted lower alkyl or benzyl group) or an ethylenimino, pyrrolidino, dimethylpyrrolidino, piperidino, methylpiperidino, hexamethylenimino, morpholino or dimethylmorpholino group.