Synthesis, antimicrobial, and anti-inflammatory activity, of novel S-substituted and N-substituted 5-(1-adamantyl)-1,2,4-triazole-3-thiols

The reaction of 5-(1-adamantyl)-4-phenyl-1,2,4-triazoline-3-thione (compound 5) with formaldehyde and 1-substituted piperazines yielded the corresponding N-Mannich bases 6a-f. The reaction of 5-(1-adamantyl)-4-methyl-1,2,4-triazoline-3-thione 8 with various 2-aminoethyl chloride yielded separable mixtures of the S-(2-aminoethyl) 9a-d and the N-(2-aminoethyl) 10a-d derivatives. The reaction of compound 5 with 1-bromo-2-methoxyethane, various aryl methyl halides, and ethyl bromoacetate solely yielded the S-substituted products 11, 12a-d, and 13. The new compounds were tested for activity against a panel of Gram-positive and Gram-negative bacteria and the pathogenic fungus Candida albicans. Compounds 6b, 6c, 6d, 6e, 6f, 10b, 10c, 10d, 12c, 12d, 12e, 13, and 14 displayed potent antibacterial activity. Meanwhile, compounds 13 and 14 produced good dose-dependent anti-inflammatory activity against carrageenan-induced paw edema in rats.

5-(Adamantan-1-yl)-3-[(2-meth-oxy-eth-yl)sulfan-yl]-4-phenyl-4H-1,2,4-triazole

In the title adamantyl derivative, C(21)H(27)N(3)OS, the terminal meth-oxy-ethyl unit is disordered over two orientations with a refined site-occupancy ratio of 0.846 (6):0.154 (6). The 1,2,4-triazole ring is statistically planar [r.m.s. deviation = 0.002 (2) Å] and the phenyl substituent is almost perpendicular to its mean plane [dihedral angle = 83.57 (11)°]. No directional inter-molecular inter-actions were observed in the crystal structure.

2-{[5-(Adamantan-1-yl)-4-methyl-4H-1,2,4-triazol-3-yl]sulfan-yl}-N,N-dimethyl-ethanamine

In the title compound, C(17)H(28)N(4)S, the 1,2,4-triazole ring is nearly planar [maximum deviation = 0.005 (2) Å]. There are no significant hydrogen bonds observed in the crystal structure. The crystal studied was a non-merohedral twin, the refined ratio of twin components being 0.281 (3):0.719 (3).

3-(Adamantan-1-yl)-4-phenyl-1-[(4-phenyl-piperazin-1-yl)meth-yl]-1H-1,2,4-triazole-5(4H)-thione

The title mol­ecule, C₂₉H₃₅N₅S, displays a chair-shaped piperazine ring, as well as an approximately planar triazole ring (r.m.s. deviation = 0.001 Å) whose phenyl substituent is nearly perpendicular to the mean plane of the five-membered ring [dihedral angle = 88.9 (1)°]. The substituents on the piperazine ring occupy equatorial sites. In the crystal, the adamantyl cage is disordered over two sets of sites with a major component of 67.8 (5)%. Weak inter­molecular C—H⋯S hydrogen bonding is present in the crystal.

3-(Adamantan-1-yl)-1-[(4-benzyl-piperazin-1-yl)meth-yl]-4-phenyl-1H-1,2,4-triazole-5(4H)-thione

The title mol­ecule, C₃₀H₃₇N₅S, displays a chair-shaped piperazine ring, as well as an approximately planar triazole ring [maximum deviation = 0.002 (2) Å] whose phenyl substituent is nearly perpendicular to the mean plane of the five-membered ring [dihedral angle = 80.4 (1)°]. The substit­uents on the piperazine ring occupy equatorial sites. Weak inter­molecular C—H⋯S hydrogen bonding is present in the crystal structure.

Ethyl 4-{[3-(adamantan-1-yl)-4-phenyl-5-sulfanyl-idene-4,5-dihydro-1H-1,2,4-triazol-1-yl]meth-yl}piperazine-1-carboxyl-ate

The title mol-ecule, C(26)H(35)N(5)O(2)S, displays a chair-shaped piperazine ring, as well as a planar triazole ring whose phenyl substituent is perpendicular to the mean plane of the five-membered ring [dihedral angle = 90.00 (13)°]. The methyl-ene substituent on the piperazine ring occupies an equatorial site. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure. The crystal studied was a non-merohedral twin, with a 33.9 (3)% minor component.