162401-62-9

3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzoic Acid (DGM,162401-62-9) is a pharmaceutical intermediate ingredient used in the preparation of Roflumilast, a selective phosphodiesterase-4 (PDE4) inhibitor approved for the treatment of chronic bronchitis and to reduce the risk of exacerbations in patients with severe chronic obstructive pulmonary disease (COPD).

An impurity and intermediate in the preparation of selective phosphodiesterase 4 (PDE4) inhibitor, Roflumilast (R639700).

It was shown that 3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzoic Acid (DGM,162401-62-9) attenuated transforming growth factor-β1 (TGF-β1)-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in rats. DGM treatment suppressed the expression of proteins such as α-SMA, waveform protein and collagen I and other proteins and increased the expression of E-cadherin. Correspondingly, the phosphorylation level of Smad2/3 was significantly reduced after DGM treatment^[1].

3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzoic Acid(162401-62-9) is synthesised using 3-cyclopropylmethoxy-4-difluoromethoxybenzaldehyde as raw material by chemical reaction. The specific synthesis steps are as follows:
3-cyclopropylmethoxy-4-difluoromethoxybenzaldehyde (12 g, 50 mmol) and sulfamic acid (7.3 g, 75 mmol) were dissolved in glacial acetic acid (50 ml) and the solution added with a solution of sodium chlorite (8.2 g, 75 mmol) in water (15 ml). The reaction mixture was stirred at room temperature for 1 hr then water (300 ml) was added so obtaining the precipitation of a solid that was filtered and dried at 40° C. under vacuum (12 g, 48 mmol, 97percent yield).

[1] TIANXIAO SUN. Inhibitory Effects of 3-Cyclopropylmethoxy-4-(difluoromethoxy) Benzoic Acid on TGF-β1-Induced Epithelial-Mesenchymal Transformation of In Vitro and Bleomycin-Induced Pulmonary Fibrosis In Vivo.[J]. International Journal of Molecular Sciences, 2023. DOI:10.3390/ijms24076172.