A method for synthesising dimethyl carbonate from methanol and urea, in which a saline ureic medium is used that includes at least one inorganic salt selected from the group made up of zinc (Zn) (II) chloride, tin (Sn) chlorides and iron (Fe) (III) chloride, characterised in that: methanol, in the presence of a catalytic composition, is placed in contact with the saline ureic medium that is at least partially liquid at a temperature referred to as synthesis temperature, which is higher than 140° C., such that reaction vapours are produced; the reaction vapours are condensed, and a condensate of the reaction vapours is collected, including dimethyl carbonate; the method is carried out at atmospheric pressure. A method for enriching and purifying dimethyl carbonate is also described.