The conversion of heterocompounds (nitrogen and sulfur) was followed during the conversion of five feedstocks: (a) naphtha from Black Thunder coal, (b) naphtha from Illinois No. 6 coal, (c) the distillate (80%) of the Black Thunder naphtha, (d) the residual (20%) portion of the Black Thunder naphtha and (e) a blend of the residual portion of the Black Thunder and the Illinois No. 6 naphtha. The presence of the heteroatoms contained in the higher molecular weight fraction retards both HDS and HDN. The lower boiling nitrogen compound classes are represented as large, or even larger, fraction of the nitrogen heterocompounds in the hydrotreated product than was present in the feed. This suggests that lower boiling anilines and pyridines are formed as intermediates during the HDN of higher boiling bicyclic nitrogen heterocompounds.