3-(Cyclopropylmethoxy)-4-(difluoromethoxy)benzoic acid is a difluoromethylated building block and intermediate typically for the synthesis of Roflumilast, a selective and long-acting inhibitor of phosphodiesterase type 4 (PDE 4) for the treatment of inflammatory conditions of the lungs such as chronic obstructive pulmonary disease(COPD).
A New Route to Roflumilast via Copper-Catalyzed Hydroxylation. 
A convenient method for the synthesis of roflumilast. 
Novel class of benzoic acid ester derivatives as potent PDE4 inhibitors for inhaled administration in the treatment of respiratory diseases. 
Catecholic amides as potential selective phosphodiesterase 4D inhibitors: Design, synthesis, pharmacological evaluation and structure–activity relationships. 
Development of highly potent phosphodiesterase 4 inhibitors with anti-neuroinflammation potential: Design, synthesis, and structure-activity relationship study of catecholamides bearing aromatic rings. 
Discovery of N-Alkyl Catecholamides as Selective Phosphodiesterase-4 Inhibitors with Anti-neuroinflammation Potential Exhibiting Antidepressant-like Effects at Non-emetic Doses. 
 F.Ni, et al, Synthesis(Germany), 2012, 44(23), pp 3598-3602.