Abstract: This invention consists of the production of a salt of acyl phosphate in an aqueous solution by a process which involves (1) acylation of phosphoric acid (H.sub.3 PO.sub.4) with an acid anhydride of the general formula RCOX, where R can be hydrogen or a lower alkyl or aryl group having from 1 to 10 carbon atoms, and X can be a leaving group of the general formula OR, OCOR, X or NR.sub.2, followed by (2a) extraction of acyl phosphate to water by treatment of the reaction mixture with an aqueous bicarbonate or hydroxide solution or other basic aqueous solution, if the reaction is carried out in non-aqueous solvent or (2b) in the case where water has been used as reaction solvent acidification with acid or acid form of a carbon exchange resin.