Vardenafil Intermediate CAS 224789-21-3 Purity >99.0% (HPLC)

1. Appearance: Put the sample on white paper and observe the appearance, off-white to pale yellow powder.
2. Analysis:
2.1 Melting Point determination according to law (Chinese Pharmacopoeia 2010 Edition II Appendix ⅥC) Melting point is 142.0~148.0℃.
2.2 Loss on Drying: Determination according to law (Appendix ⅧL, Part II, 2010 Edition of Chinese Pharmacopoeia). Precision weighing appropriate amount of this product, dry at 102℃ for 3 hours, weight loss shall not be more than 1.00%.
2.3 Heavy Metals: Determination according to law (People's Republic of China Pharmacopoeia 2010 Edition, Part II Appendix ⅧH) Determination by the second method.
Precision weigh 1.0g of the test product, slowly burning until completely carbonized, cool, add 0.5-1.0ml sulfuric acid, make it moist, heat at low temperature until the sulfuric acid is exhausted, add 0.5ml nitric acid, steam dry, until the nitrogen oxide vapor is exhausted, cool, hot at 500-600℃ to completely carbonized, cool, add 2ml hydrochloric acid, After drying in a water bath, add 15ml water, drop the ammonia test solution until it becomes neutral to the phenolphthalein indicator solution, add 2ml acetate buffer (ph3.5), and slightly heat dissolve, move it to the Nachner colorimetric tube, and dilute it into 25ml with water. Take another reagent for preparing the test solution, and steam it in a porcelain dish, add 2ml acetate buffer (PH3.5) and 15ml water to slightly heat After dissolution, move the Nath colorimetric tube, add a certain amount of standard lead solution, and then dilute with water to 25ml. Colorimetric experiment is carried out between test solution and standard solution to obtain. Standard solution preparation according to (People's Republic of China Pharmacopoeia 2010 edition II Appendix Ⅷ Heavy metal test method) the first method. Heavy metals must not exceed 20 parts per million.
3. Purity: According to high performance liquid chromatography, determined according to law (Chinese Pharmacopoeia 2010 edition II Appendix VD).
Chromatographic conditions:
Column: C18, 200mm×4.6mm, 5μm;
Mobile phase: Phosphate buffer (weigh 2.72g potassium dihydrogen phosphate, add water to dissolve and dilute to 1000ml, adjust pH=3.5) : acetonitrile: = 35:65;
Detection wavelength: 254nm;
Flow rate: 1.0ml/min.
Determination method: Take about 30mg of this product, weigh it accurately, dilute it with mobile phase to make the concentration of about 0.3mg/ml, take 20μl into the liquid chromatograph, record the chromatogram. According to area normalization method, the purity is not less than 99.0%.