Two-stage reduction and reductive alkylation of coal using deuterium-labelled modifying agents

Coal conversion caused by a two-stage reduction or alkylation in the potassium/liquid ammonia system was studied. The modifying agents were: C2H5OD and CD3I for the reduction and alkylation, respectively. Analogous processes were also performed by the conventional method. It was found that the reduction and reductive alkylation of coal with the use of deuterium-labelled modifying agents provided more information about these processes and about the coal structure than when performed with the conventional method. The kind of hydrogen isotope had no effect on the coal transformation to products soluble in dichloromethane. The two-stage reduction and alkylation resulted in an increase of the number of substituents introduced into coal compared with that introduced in the one-stage process. It has been observed that during the reduction and reductive alkylation, apart from certain substituents originating from the modifying agent, also considerable amounts of ammonia-originated hydrogen were introduced into the coal structure.