about 25 u00b0 c about 15 u00b0 c to about 20 u00b0 c is preferred after mixing is complete agitation is continued for about 0 5 hour to about 1 5 hours and the temperature of the mixture is held between about 20 u00b0 c and about 25 u00b0 c additional dichloromethane is charged with agitation agitation is stopped and the dichloromethane layer is separated the aqueous layer 39 s temperature is controlled between about 20 u00b0 c to about 25 u00b0 c an amount of propylene oxide in excess of the hydrogen chloride that could theoretically be produced from total hydrolysis of the phosphorous oxychloride used in the phosphorylation reaction is dissolved in ethanol with vigorous agitation and the temperature adjusted between about 20 u00b0 c to about 25 u00b0 c the aqueous layer containing the 9 u03b2 d arabinofuranosyl adenine 5 39 phosphate is added to the propylene oxide solution while holding the temperature at about 20 u00b0 c to about 25 u00b0 c with cooling the desired product 9 u03b2 d arabinofuranosyl adenine 5 39 phosphate crystallizes smoothly from the ethanol water mixture and can be isolated by filtration or centrifugation after vacuum drying at about 40 u00b0 c u00b1 5 u00b0 c for about 24 hours to about 48 hours the material ordinarily meets all specifications and is obtained in high yield additionally the 9 u03b2 d arabinofuranosyl adenine 5 39 phosphate from this process may be further purified by suspending the compound in water with agitation at about 20 u00b0 c to about 25 u00b0 c the ph is adjusted to a ph 6 0 u00b1.