An amide compound of formula 1: ##STR1## wherein R is 1,2,3,4-tetrahydro-1-naphthyl, 1,4-dihydro-1-naphthyl or 3,4-dihydro-1-naphthyl; R.sub.1 is hydrogen or methyl; R.sub.2 is hydrogen or an alkyl; Ar is a phenylene group; and X is hydrogen, a halogen, methyl or methoxy. This amide is useful as a herbicide.