The invention comprises compounds having the formula: <FORM:0783828/IV (a)/1> wherein Ar represents a phenyl, naphthyl, biphenyl, furyl, pyridyl or thienyl radical, X is a lower alkylene radical having one to four carbon atoms, Y is a lower a ,b -alkylene radical having two to four carbon atoms, R represents hydrogen or a hydrocarbon radical having from one to eight carbon atoms and Ac is a halogenated-(lower alkanoyl) radical having from two to four carbon atoms, compounds having the formula: <FORM:0783828/IV (a)/2> in which Z is halo or lower alkoxy and m is an integer from 1 to 3 inclusive and a process for the preparation of a compound having the formula I, which comprises reacting a compound having the formula: Ar-X-NH-Y-CONH-R with an acylating agent having the formula Ac-halogen or (Ac)2O, e.g. dichloroacetyl hloride or trichloroacetyl chloride. Examples describe the production of compounds having the formula: <FORM:0783828/IV (a)/3> whereinQ represents 2,4-di-Cl, H, 4-CH3, 4-OC4H4-n, 4-CH(CH3)2, 3,4-di-OCH3, 4-Cl, and 4 - N(CH3)2, N - phenylethyl - N - (2 - carbamylethyl - dichloracetamide, N - (1 - naphthylmethyl) - N - (2 - carbamylethyl) - dichloracetamide, N - (1 - biphenylmethyl) - N - (2-carbamylethyl) - dichloracetamide, N - (4 - n - hexylbenzyl) - N - (2 - carbamylethyl) - dibromoacetamide, N - (2,4 - diiodobenzyl) - N - (2-carbamylethyl) - bromochloroacetamide, N-(4 - nitrophenathyl) - N - (2 - carbamylethyl)-diiodoacetamide, N - [1 - (3,4,5 - triethoxyphenyl)ethyl] - N - (2 - carbamylpropyl)dichloroacetamide, N - [4 - (2,4 - dichlorophenyl) butyl] - N - (2 - carbamylpropyl) - 2,2 - dichloropropanamide, N - (4 - di - n - butylaminobenzyl) - N - (2 - carbamylbutyl) - 2,2 - diiodopropanamide, N - (4 - n - hexyloxybenzyl) - N-(2 - carbamylethyl) - 2 - bromo - 3 - chloropropanamide, N - (4 - n - butyl - mercaptobenzyl)-N - (2 - carbamylethyl) - 2,2,3 - trichloropropanamide, N - (4 - n - butylsulphonylbenzyl) - N-(2 - carbamylethyl) - 2,2 - dichlorobutanamide, N - (2,4 - dichlorobenzyl) - N - (2 - carbamylethyl) - 3,4 - dibromobutanamide, N - (4 - n-butoxybenzyl) - N - (2 - carbamylethyl) - 2,2,3-trichlorobutanamide, N - (4 - chlorobenzyl)-N - (2 - carbamylethyl) - 2,3,4 - trichlorobutamide, N - (2 - furylmethyl) - N - (2 - carbamylethyl) - dichloroacetamide, N - (2 - thienylmethyl) - N - (2 - carbamylethyl) - dichloroacetamide, N - (2 - pyridylmethyl) - N - (2-carbamylethyl) - dichloroacetamide, N - (3-pyridylmethyl) - N - (2 - carbamylethyl) - dichloroacetamide, N - (5 - chloro - 2 - pyridylmethyl) - N - (2 - carbamylpropyl) - dichloroacetamides, N - (4 - n - butoxybenzyl) - N - (2-carbamylethyl) - trichloroacetamide, N - (4-chlorobenzyl) - N - (2 - carbamylethyl) - trichloroacetamide, N - benzyl - N - (2 - carbamylethyl) - trichloroacetamide, N - phenylethyl-N - (2 - carbamylethyl) - trichloroacetamide, N - (2,4 - dichlorobenzyl) - N - (2 - carbamylethyl) - trichloroacetamide, N - (4 - isopropylbenzyl) - N - (2 - carbamylethyl) - trichloroacetamide, N - (3,4,5 - triiodobenzyl) - N - (2-carbamylethyl) - trichloroacetamide, N - (2,4-dichlorophenethyl) - N - (2 - carbamylethyl)-trichloroacetamide, N - (4 - isobutylbenzyl)-N - (2 - carbamylbutyl) - trichloroacetamide, N - (3,4 - dibromobenzyl) - N - (2 - carbamylpropyl) - tribromoacetamide, N - (4 - chlorobenzyl) - N - (2 - carbamylethyl) - chloracetamide, N - (2,4 - dichlorobenzyl) - N - (2 - carbamylethyl) - chloracetamide, N - (3,4 - dimethoxybenzyl) - N - (2 - carbamylethyl) - 3 - chloropropanamide, N - (4 - n - butoxybenzyl)-N - (2 - carbamylethyl) - 4 - bromobutanamide, N - (3,4 - dibromobenzyl) - N - (2 - carbamylethyl) - bromoacetamide, N - (4 - n - hexylbenzyl) - N - (2 - carbamylbutyl) - fluoroacetamide, N - (2,4 - diiodobenzyl) - N - (2 - carbamylpropyl) - iodoacetamide, N - (2,4 - dichlorophenethyl) - N - (2 - carbamylethyl) - chloracetamide, N - (4 - isopropylbenzyl) - N - [2-(ethylcarbamyl)ethyl]dichloroacetamide, N-[4 - isopropylbenzyl) - N - [2 - (n - hexylcarbamyl)ethyl]dibromoacetamide, N - (2,4 - dichlorobenzyl) - N - [2 - allylcarbamyl)ethyl]-trichloroacetamide, N - (4 - n - butoxybenzyl)-N - [2 - (cyclopentylcarbamyl)propyl]iodoacetamide, N - (3,4 - dibromobenzyl) - N - [2 - cyclohexylmethylcarbamyl)ethyl] - 2,2 - dichloroprepanamide, N - (4 - chlorobenzyl) - N - [2-(phenylcarbamyl)butyl] - 2,3 - dichloropropanamide, N - [2 - (3,4 - diethoxyphenyl)ethyl]-N - [2 - (3-ethylphenylcarbamyl)ethyl] - 2,3,4-trichlorobutanamide, N - (2,4 - dichlorobenzyl)-N - [2 - (benzylcarbamyl)ethyl] - 2,2 - dibromobutanamide and N - (4 - nitrobenzyl) - N - [2-(phenethylcarbamyl) ethyl] dichloroacetamide. The intermediate compounds Ar-X-NH-Y-CONH2 are obtained by reacting an aralkylamine Ar-X-NH2 with a 2-alkenamide, e.g. N - (2 - carbamylethyl) - 2,4 - dichlorobenzylamine is obtained by reacting 2,4-dichlorobenzene with acrylamide.