The interaction between coal and model compounds at relatively mild conditions was investigated to explore effects of coal, solvent, and reaction conditions at low coal conversions. Five coals were reacted with five model compound solvents (eicosane, 1-phenyldodecane, 1,4-diisopropylbenzene, 1,2,4,5-tetramethylbenzene, and pyrene) at 350, 400, and 450 degrees C. The coals were subbituminous and high-volatile bituminous rank. and were selected to have very low concentrations of pyritic sulfur, to minimize catalytic effects of mineral matter. The effects of temperature, gas atmosphere (N-2 or H-2), and solvent on conversion to THF-solubles were investigated. Catalysts were not used. Conversions were influenced by temperature, which directly affected the coal and the solvent behavior. The optimum temperature for conversion appears to be 400 degrees C. Conversions were lowest at 350 degrees C, and; in some cases, were lower at 450 degrees C than at 400 degrees C. The thermal decomposition behavior of the coal is more important in determining total yields of THF-solubles than is the dissolving power of the solvent. Hydrogen improved conversion in the absence of a solvent, but the role of H-2 was not so pronounced when a solvent was used. The most effective solvent for enhancing coal conversion was pyrene. Vapor/liquid liquid partitioning of the solvents was not a major factor in affecting conversions. The thermoplastic properties of the coals are related to the extent of coal conversion. Under our conditions, caking coals reacted in pyrene in H-2 give the highest conversions. The maximum conversion achieved was 43 wt % which indicates certain limits in coal conversions under the given conditions.