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4-(3-Chloro-4-methoxybenzylamino)-5-ethoxycarbonyl-2-methylthiopyrimidine is an intermediate for Avanafil (A794670) derivatives. Avanafil is a phosphodiesterase (PDE5) inhibitor, used to treat erectile dysfunction.

General procedure for the synthesis of 4-(3-chloro-4-methoxybenzylamino)-2-methylmercapto-5-ethoxycarbonylpyrimidine from 4-chloro-2-methylthiopyrimidine-5-carboxylic acid ethyl ester and 3-chloro-4-methoxybenzylamine: firstly, 3-chloro-4-methoxybenzylamine (45.6 g, 0.27 mol) was dissolved in 180 mL of acetone, followed by triethylamine (40.4 g, 0.4 mol). Next, ethyl 4-chloro-2-methylthiopyrimidine-5-carboxylate (53.3 g, 0.24 mol) was dissolved in 250 mL of acetone and slowly added dropwise to the above reaction solution. The reaction was carried out at room temperature for 3 hours. Upon completion of the reaction, the reaction solution was poured into an ice-water mixture and extracted with ethyl acetate. The organic phases were combined and washed with 10% aqueous citric acid (250 mL x 3). The organic layer was dried with anhydrous sodium sulfate, followed by evaporation of the solvent under reduced pressure. Finally, the product was dried under vacuum to give a white solid (86.0 g, 87.0% yield).

[1] Bioorganic and Medicinal Chemistry Letters, 2014, vol. 24, # 23, p. 5460 - 5465
[2] Bioorganic and Medicinal Chemistry Letters, 2015, vol. 25, # 7, p. 1431 - 1435
[3] Patent: CN108707141, 2018, A. Location in patent: Paragraph 0027; 0031; 0036; 0040; 0045; 0049
[4] Patent: EP2886540, 2015, A1. Location in patent: Paragraph 0168; 0169
[5] Patent: EP1366760, 2003, A1. Location in patent: Page 19