A process, which process includes the following steps: a) converting a solid material containing hemicellulose, cellulose and lignin, by: (i) hydrolyzing, at a temperature equal to or less than 40 °C, preferably equal to or less than 30 °C, at least part of the hemicellulose of the solid material with a first aqueous hydrochloric acid solution, which first aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 15.0 wt. % to less than 40.0 wt. %, based on the weight amount of water and hydrochloric acid in such first aqueous hydrochloric acid solution, yielding a remaining solid material and a hydrochloric acid-containing, aqueous, first hydrolysate product solution; (ii) hydrolyzing, at a temperature equal to or less than 40 °C, preferably equal to or less than 30 °C, at least part of the cellulose of the remaining solid material with a second aqueous hydrochloric acid solution, which second aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 40.0 wt. % to equal to or less than 51.0 wt. %, based on the weight amount of water and hydrochloric acid in such second aqueous hydrochloric acid solution, yielding a residue and a hydrochloric acid-containing, aqueous, second hydrolysate product solution. (b) forwarding to step (c) a hydrochloric acid-containing, aqueous intermediate product solution comprising: - a part of or the whole of the hydrochloric acid-containing, aqueous first hydrolysate product solution of step (a); and/or - a part of or the whole of the hydrochloric acid-containing, aqueous second hydrolysate product solution of step (a); and (c) heating at least part of the hydrochloric acid-containing, aqueous intermediate product solution to a temperature equal to or more than 60 °C, yielding a product solution containing 5-(chloromethyl)furfural, and extracting the 5-(chloromethyl)furfural from such product solution into an extraction solvent. a) converting a solid material containing hemicellulose, cellulose and lignin, by: (i) hydrolyzing, at a temperature equal to or less than 40 °C, preferably equal to or less than 30 °C, at least part of the hemicellulose of the solid material with a first aqueous hydrochloric acid solution, which first aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 15.0 wt. % to less than 40.0 wt. %, based on the weight amount of water and hydrochloric acid in such first aqueous hydrochloric acid solution, yielding a remaining solid material and a hydrochloric acid-containing, aqueous, first hydrolysate product solution; (ii) hydrolyzing, at a temperature equal to or less than 40 °C, preferably equal to or less than 30 °C, at least part of the cellulose of the remaining solid material with a second aqueous hydrochloric acid solution, which second aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 40.0 wt. % to equal to or less than 51.0 wt. %, based on the weight amount of water and hydrochloric acid in such second aqueous hydrochloric acid solution, yielding a residue and a hydrochloric acid-containing, aqueous, second hydrolysate product solution. (i) hydrolyzing, at a temperature equal to or less than 40 °C, preferably equal to or less than 30 °C, at least part of the hemicellulose of the solid material with a first aqueous hydrochloric acid solution, which first aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 15.0 wt. % to less than 40.0 wt. %, based on the weight amount of water and hydrochloric acid in such first aqueous hydrochloric acid solution, yielding a remaining solid material and a hydrochloric acid-containing, aqueous, first hydrolysate product solution; (ii) hydrolyzing, at a temperature equal to or less than 40 °C, preferably equal to or less than 30 °C, at least part of the cellulose of the remaining solid material with a second aqueous hydrochloric acid solution, which second aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 40.0 wt. % to equal to or less than 51.0 wt. %, based on the weight amount of water and hydrochloric acid in such second aqueous hydrochloric acid solution, yielding a residue and a hydrochloric acid-containing, aqueous, second hydrolysate product solution. (b) forwarding to step (c) a hydrochloric acid-containing, aqueous intermediate product solution comprising: - a part of or the whole of the hydrochloric acid-containing, aqueous first hydrolysate product solution of step (a); and/or - a part of or the whole of the hydrochloric acid-containing, aqueous second hydrolysate product solution of step (a); and - a part of or the whole of the hydrochloric acid-containing, aqueous first hydrolysate product solution of step (a); and/or - a part of or the whole of the hydrochloric acid-containing, aqueous second hydrolysate product solution of step (a); and (c) heating at least part of the hydrochloric acid-containing, aqueous intermediate product solution to a temperature equal to or more than 60 °C, yielding a product solution containing 5-(chloromethyl)furfural, and extracting the 5-(chloromethyl)furfural from such product solution into an extraction solvent.