A process for the transformation of a feed of at least one sugar into 5-hydroxymethylfurfural, contacting the feed with one or more organic catalysts in the presence of at least one solvent, said solvent being water or an organic solvent, alone or as a mixture, at a temperature in the range 30° C. to 200° C., and at a pressure in the range 0.1 MPa to 10 MPa, in which said organic catalysts are selected from compounds from the thiourea family with general formula R1NH—C(═S)—NHR2, in which the groups R1 and R2 are aromatic groups optionally having a heteroatom, linear or branched alkyl groups, which may or may not be cyclic, and alkyl groups with at least one heteroatom, which may be linear or branched, which may or may not be cyclic, said groups R1 and R2 possibly being substituted or unsubstituted and which may be identical or different.