NOVELTY - Preparation of 2,5-dimethylfuran comprises: (a) combining a source of carbohydrate with a carboxylic acid; (b) heating the reaction mixture of step (a) to a temperature sufficient to form 5-(hydroxymethyl)furfural (HMF) and/or its ester; (c) adding a first catalyst to the reaction mixture of step (b) and optionally an aprotic solvent; and (d) heating the reaction mixture of step (c) to form 2,5-dimethylfuran.    USE - The process is useful for preparing 2,5-dimethylfuran or its derivative (claimed) from carbon neutral precursors, where the 2,5-dimethylfuran is useful as liquid biofuel.    ADVANTAGE - The method: is one pot synthesis for preparing 2,5-dimethylfuran; avoids the isolation of intermediates, hence the process is cost-effective; does not require the use of hazardous substances; does not generate hazardous substance and unwanted waste; and employs green reagents (formic acid and acetic acid). The method provides 2,5-dimethyl furan from renewable carbon neutral precursors.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) preparing 2,5-dimethylfuran comprising: steps (a) and (b), (c1) adding hydrogen, a first catalyst, and optionally an aprotic solvent to the reaction mixture of step (b), (d1) reacting the mixture of step (c1) to form 2,5-bis(hydroxymethyl)furan (BHMF), (e1) adding a second catalyst to the reaction mixture of step (d1) to form an ester of BHMF, and (f1) hydrogenolysis of the ester of step (e1) to form 2,5-dimethylfuran; and    (2) a method for preparing dimethylfuran or its derivative comprising: combining a furan compound of formula (a2) with a carboxylic acid and a strong acid catalyst, heating the reaction mixture to a temperature sufficient to form an ester of (a2), adding an aprotic solvent and a first catalyst to the reaction mixture, and heating the reaction mixture under hydrogen to form a product comprising DMF, 2,5-dimethyltetrahydrofuran, 2-methylfuran or 2-methyltetrahydrofuran.    R1, R2 = H, CH2OH, CH3 or CH(=O).