Structure of Ethyl [3-(4-chlorophenyl)-5-methyl-4H-1,2,4-triazol-4-yl]carbamate

Abstract

Triazoles are one important class of heterocyclic compounds with important biological and pharmacological properties. A wide range of substituted triazole derivatives exhibit biological activities, such as herbicides, bactericides, pesticides and fungicides. 1,2 The title compound (I, Fig. 1) was synthesized to investigate its possible biological activities. The two-step synthesis of I involves, first, amide formation, and then cyclization reactions. In a 50 ml round-bottom flask fitted with a magnetic stir bar, 0.870 g (5 mmol) of ethyl 2-(1-ethoxy ethyli-dene)hydrazinecarboxylate, which was prepared according to a literature procedure, 3 was mixed with 0.853 g (5 mmol) of 4-chlorobenzohydrazide (Fluka). The mixture was heated to melt in an oil bath at around 110-115˚C and refluxed for an additional 2 h at 130˚C. Thereafter, the mixture was allowed to cool to the room temperature to give a colorless, viscous oil. A 5 ml portion of petroleum ether was added to the flask and left standing overnight at 0-2˚C. The precipitate was filtered and washed with alcohol, dried in vacuo and recrystallized from dichloromethane/abs. ethanol (1:1 v/v) to give 0,754 g of I (54% yield); m.p., 192-193˚C. A colorless block crystal of I having approximate dimensions of 0.50 × 0.40 × 0.20 mm was selected for X-ray diffraction studies. The crystal and experimental data are given in Table 1.