ESI-MS fragmentation pathways of some 1,2,4-triazole-3-thiones, the intermediate compounds in the synthesis of active pharmaceutical ingredients

Abstract

ESI-MS fragmentation pathways of some 1,2,4-triazole-3-thiones, the intermediate compounds in the synthesis of active pharmaceutical ingredients Aim. To determine the fragmentation pathways of eight 1,2,4-triazole-3-thiones, which are intermediate products in the synthesis of active pharmaceutical ingredients of potential and registered pharmaceutical formulations. Results and discussion. HPLC-MS analysis of eight 1,2,4-triazole-3-thiones, which are intermediate products in the synthesis of salts of 1,2,4-triazolylthioacetate acids, has been carried out; the mass spectra of the compounds to be analyzed have been registered in ESI-mode with different fragmentor voltage (0, 100, 200 V). The fragmentation pathways and patterns of ion decay for compounds to be analyzed have been proposed. Experimental part. Agilent 1260 Infinity HPLC System with Agilent 6120 mass spectrometer were used. HPLC-MS conditions: column-∅4,6 × 30 mm, reversible phase Zorbax SB C18, 1.8 μm, 40 o C; mobile phase-0.1 % HCOOH in H 2 O and 0.1 % HCOOH in СH 3 CN in isocratic mode (50:50, v/v); the flow rate-0.4 mL/min; ion source-API-ES; positive polarity; drying gas-nitrogen (rate-10 L/min); the capillary voltage-4000 V; scanning in the range of m/z 100-1000. Conclusions. For the first time it has been interpreted the mass spectra of 1,2,4-triazole-3-thiones series, the intermediate compounds in the synthesis of active pharmaceutical ingredients of pharmaceutical formulations. The fragmentation pathways and patterns of eight 1,2,4-triazole-3-thiones have been shown.

Silica Gel Functionalized with 4‐Amino‐5‐(4pyridyl)‐4H‐1,2,4‐triazole‐3‐thiol and their Use as a Copper Sorbent and Electromediator for Voltammetric Detection of Ascorbic Acid

“…The tautomerism in triazoles is called Dimroth rearrangement and occurs due to opening and subsequent ring recyclization, in other words, indicates the migration of double bond. Thus, there are two different tautomeric forms: the thione and the thiol, in the transition of group thione, the double bond occurs between the sulfur and carbon and the transition of group thiol, the double bond occurs between the nitrogen and carbon .…”