Facile synthesis of 5β-cholane-sym-triazine conjugates starting from metformin and bile acid methyl esters: Liquid and solid state NMR characterization and single crystal structure of lithocholyl triazine

Four bile acid-triazine conjugates: N2′,N2′-dimethyl-6′-(3α-hydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (lithocholyl triazine, 4a), N2′,N2′-dimethyl-6′-(3α,7α-dihydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (chenodeoxycholyl triazine, 4b), N2′,N2′-dimethyl-6′6′-(3α,12α-dihydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (deoxycholyl triazine) (4c), and N2′,N2′-dimethyl-6′-(3α,7α,12α-trihydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (cholyl triazine) (4d) have been prepared and characterized by liquid and solid state NMR. An improved synthetic method produced better yields and an easier purification procedure for 4d than reported in the literature. Single crystal structure of 4a is reported: empirical formula C28H47N5O, monoclinic P21 space group with unit cell dimensions, a 18.7135(5) A, b 7.4510(2) A, c 19.3073(5) A, β 95.7290(10)°, volume 2678.65(12) A3.