24 72 hours the temperature of reaction is not critical any temperature above the freezing point of the solution to the boiling point of chloroacetaldehyde 85 u00b0 c can be used although a preferred temperature range is about 20 u00b0 50 u00b0 c and room temperature is usually suitable for forming the solution of the coenzyme and chloroacetaldehyde any solvent which is compatible with the reactants can be used water is preferred although organic solvents such as ethanol isopropyl alcohol dimethyl formamide and acetonitrile can also be used the concentration of the solution is similarly not critical and is limited only by the solubility of the reactants in the selected solvent concentrations on the order of 1 0 2 0 molar are typical and can be used effectively illustrative of the compounds of the invention are those whose properties are given below in table i these compounds were prepared by stirring a solution of 2 millimoles of the adenosine derivative in 20 ml of 2m aqueous chloroacetaldehyde at ph 4 0 4 5 for 24 72 hours at a temperature of 20 u00b0 72 u00b0 c the resulting reaction product was decolorized with charcoal and evaporated to dryness under vacuum reprecipitation of the residue from aqueous ethanol was followed by an ethanol wash to yield pure product the compounds listed in table i were made following this method each pure product was.