FIELD: industrial organic synthesis. SUBSTANCE: production of C10-C14-n-alkylbenzenes useful as detergent intermediates includes following stages: (i) dehydrogenation of C10-C14-n-paraffins into corresponding n-paraffins in dehydrogenation reactor to form mixture containing also diolefins and aromatic by-products as well as light decomposition products and hydrogen; (ii) selective hydrogenation of diolefins obtained in stage (i) into monoolefins to form mixture consisting essentially of monoolefins and n-paraffins in addition to aromatic by-products from stage (i); (iii) feeding stream coming out of stage (ii) in common with benzene-containing stream into alkylation apparatus incorporating alkylation catalyst; (iv) feeding alkylation product into distillation section, wherein excess benzene is removed and paraffin stream containing essentially C10-C14-n-paraffins and aromatic byproducts and stream containing alkylated aromatic product are isolated; (v) hydrogenation of paraffin stream; and (vi) recycling stream from stage (v) into (i)-stage dehydrogenation apparatus. Process is distinguished by that aromatic by- products formed in dehydrogenation stage and contained in paraffin stream coming out of alkylation section are converted in cycloparaffins in (v)-stage hydrogenation operation. EFFECT: improved selectivity of process. 10 cl, 10 tbl, 6 ex
