Stereoselective Synthesis of New 4-Aryl-5-indolyl-1,2,4-triazole S- and N-β-Galactosides: Characterizations, X-ray Crystal Structure and Hirshfeld Surface Analysis

5-(1H-Indol-2-yl)-4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione 1a and 4-(4-chlorophenyl)-5-(1H-indol-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 1b were galactosylated in the presence of NaHCO3 ethanol to produce S-galactosides 3,4, whereas, K2CO3 acetone they produced a mixture S- N-galactosides 3-6 with higher yield over respective N-galactosides. Improvement yields was by thermal migration galactosyl moiety from sulfur nitrogen using fusion. β-Stereoselectivity galactosylation determined coupling constant value 3J1,2, which exceeded 9.0 Hz all prepared galactosides. The precursors alkylated 3-bromopropan-1-ol 7 S-alkylated products 8 9, respectively. Structural determinations new compounds 5 9 are presented. phenyl indole moieties found be twisted triazole ring mean both compounds. For compound 5, twist angles 66.24° 18.86°, respectively, while corresponding values for ranges 73.15–77.29° 13.96–20.70°, Hence, crystal system is triclinic space group P-1. Detailed analysis intermolecular interactions structure presented Hirshfeld calculations. O…H, N…H, C…H, S…H contacts appeared as red spots dnorm surface indicating short distance interactions. Their percentages estimated based on decomposition fingerprint plot 25.6, 2.4, 14.0, 6.3%,