related specific compounds in addition to the compounds shown in the examples are as follows this invention is further illustrated by examples hereinafter also growth inhibitory activities on plants of the compounds of the invention are shown in reference examples a mixture of 3 0 g 8 5 mmol m p 110 u00b0 112 u00b0 c of 1 butyl n 2 6 diethylphenyl 1 4 dihydro 2 6 dimethyl 4 oxo 3 pyridinecarboxamide and 1 7 g 9 6 mmol of n bromosuccinimide was dissolved in 100 ml of dichloromethane and the mixture was stirred for a day at room temperature the reaction mixture transferred to a separatory funnel was washed with water saturated sodium bicarbonate and water the organic layer was dried and concentrated in a known manner to give a crystalline residue and the residue was recrystallized from a mixture of ethyl acetate and hexane affording 2 25 g of the title compound having m p 158 u00b0 160 5 u00b0 c a mixture of 500 mg 1 41 mmol m p 110 u00b0 112 u00b0 c of 1 butyl n 2 6 diethylphenyl 1 4 dihydro 2 6 dimethyl 4 oxo 3 pyridinecarboxamide and 188 mg 1 41 mmol of n chlorosuccinimide was dissolved in 15 ml of chloroform and refluxed with stirring to the reaction mixture 190 mg of n chloro succinimide was added in twice and refluxed for 15 2 hours the reaction mixture transferred to a separatory funnel was washed with water saturated sodium bicarbonate and water the organic layer was dried and concentrated in a usual manner to give a yellow oil which was purified by column chromatography waco gel u00ae c 200 with a mixture of ethyl acetate and hexane a crystalline residue was recrystallized.