Tổng hợp và xác định độ tinh khiết tạp chất liên quan D (ethyl 5-amino-1H-pyrazol-4-carboxylat) của alopurinol

Abstract

Allopurinol impurity D (ethyl 5-amino-1 H-pyrazole-4-carboxylate) was synthesized from ethyl (ethoxymethylene) cyanoacetate and hydrazine in the yield of 61.3 % (0.28 gram). By using HPLC - PDA, its chromatographic purity was determined over 99.0 %. As such, the obtained allopurinol impurity D was fairly satisfactory for establishment of the reference substance. Moreover, an HPLC method for purity determination of impurity D was developed as: column - XtimateR C18(5 µm; 250 x 4.6 mm); Detector- UV (247 nm; Mobile phase - methanol and water (40:60, v/v); Flow rate -1.0 mUmin. Validation in observance to ICH guidelines, the method showed to hand wide linearity range (25.16 - 503.10 µg/ml), high precision (RSD < 0.03 %). The method showed good selectivity, wide linearity range and high precision.