Methyl 1-((2-acetoxyethoxy)methyl)-5-bromo-1H-1,2,4-triazole-3-carboxylate (32.2 mg, 0.1 mmol), the corresponding 4-benzenethiol (0.12 mmol), and K₂CO₃ (27.6 mg, 0.2 mmol) were suspended in 2 mL of fresh distilled CH₃CN under argon. The vessel was sealed and the reaction was carried out under microwave irradiation at 100˚C for 30 min, and then cooled to room temperature. The reaction mixture was concentrated under reduced pressure and the crude residue was purified by flash chromatography on silica gel (petroleum ether/ethyl acetate, 2:1). The purified material was dried in vacuo to afford the corresponding product as colorless oil, an amount of 35.2 mg of compound 2 was obtained with a excellent yield of 99%.

The solution of NH₃/MeOH (18 mL) was added to a flask contammg compound 1 (90.6 mg, 0.258 mmol), and the mixture was stirred at room temperature until two days. After removal of the solvent, the compound 4 (63.9 mg, 84%) was obtained as a white solid.

White crystals suitable for XRD formed after a few days of slow evaporation of the solvent at room temperature over several days. Yellow single crystals of the title compound are shown in Figure 1. The crystal structures of 1 clearly revealed that it has well-defined geometry due to the rigidity that the fused rings confer on the molecule.

All reagents obtained from commercial sources were of AR grade. Melting points were determined with XT4A micromelting point apparatus and were uncorrected. The ¹H NMR was recorded on a Mercury Plus-400 spectrometer with TMS as internal reference and CDCl₃ as solvent. IR were recorded on a Perkin-Elmer PE-983 IR spectrometer as KBr pellets with absorption in cm⁻¹. MS were obtained with Finnigan Trace MS instrument using EI method. Elemental analyses were carried out on a Vario EL III instrument.

Single crystal X-ray diffraction studies were carried out on the grown crystals. The X-ray date were collected using X-ray diffractometer (Model: Bruker Smart APEX-CCD). A white crystal of the title compound 4 was each mounted on a glass fibre in a random orientation at 298(2) K. The determination of the unit cell and the data collection were performed with MoKa radiation (l = 0.71073 Å) on a Bruker Smart Apex-CCD diffactometer with a y-w scan mode. The structure was solved by direct methods with SHELXS-97 program and expanded by Fourier technique. The non-hydrogen atoms were refined anisotropically, and the hydrogen atoms were placed at the calculated positions.

Crystal data for 2: C₁₂H₁₄N₃0₄S, M = 294.33, Triclinic, space group P2(1)/n, a = 7.347(2) Å, b = 26.952(7) Å, c = 7.708(2) Å, α = 90˚, β = 116.505(5)˚, γ = 90˚, V = 1365.7(6) ų, Z = 4, Dc = 1.431 Mg/m³. Reflections collected: 8719, independent reflections: 2675 [R_int = 0.1147, Final R indices [I > 2 sigma(I)]: R¹ = 0.0686, wR² = 0.1291. R indices (all data): R¹ = 0.1183, wR² = 0.1475.

Compound of 1. ¹H NMR (300 MHz, CDCl₃): d 7.51 - 7.54 (m, 2H, phenyl-H), 7.36 - 7.38 (m, 3H, phenyl-H), 5.66 (s, 2H,-OCH₂N-), 4.13 (t, 2H, J = 4.7 Hz, -OCH₂CH₂OAc), 3.99 (s, 3H, -OCH₃), 3.76 (t, 2H, J = 4.7 Hz, -OCH₂CH₂OAc), 2.05 (s, 3H, -C(O)CH₃); ¹³C NMR (150 MHz, CDCl₃): d 170.9, 159.9, 154.6, 153.5, 132.3, 129.8, 129.2, 78.4, 67.9, 62.8, 53.1, 21.0; Maldi-MS: m/z 352.1 [M + H]⁺; HRMS: calcd. for C₁₅H₁₈N₃O₅S⁺ 352.0962, found 352.0951.

Compound of 2. ¹H NMR (300 MHz, CDCl₃): d 7.93 (br s, 1H, -C(O)NH₂), 7.70 (br s, 1H, -C(O)NH₂), 7.39 - 7.51 (m, 5H, phenyl-H), 5.66 (s, 2H, -OCH₂N-), 4.74 (t, 1H, J = 5.4 Hz, -OH), 3.51 - 3.55 (m, 2H, -OCH₂CH₂OH), 3.44 - 3.47 (m, 2H, -OCH₂CH₂OH); ¹³C NMR (75 MHz, DMSO-d₆): d 160.5, 157.7, 151.4, 131.7, 130.9, 130.3, 129.2, 78.7, 71.8, 60.4; Maldi-MS: m/z 295.1 [M + H]⁺; HRMS: calcd. for C₁₂H₁₅N₄O₃S⁺ 295.0859, found 295.0853.