The biomolecule, 2-[(2-methoxyl)sulfanyl]-4-(2-methylpropyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile: FT-IR, Laser-Raman spectra and DFT.

In this study, the experimental and theoretical vibrational frequencies of a newly synthesized potential chemotherapeutic agent namely, 2-[(2-methoxyl)sulfanyl]-4-(2-methylpropyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile have been investigated. The experimental FT-IR (4000-400cm(-1)) and Laser-Raman spectra (4000-100cm(-1)) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and bond angles) have been calculated by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set by Gaussian 09W software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis by using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data, and with the results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated using the same theoretical calculations.

Experimental FT-IR, Laser-Raman and DFT spectroscopic analysis of a potential chemotherapeutic agent 6-(2-methylpropyl)-4-oxo-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carbonitrile.

In this study, the experimental and theoretical vibrational frequencies of a newly synthesized potential chemotherapeutic agent namely, 6-(2-methylpropyl)-4-oxo-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carbonitrile have been investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and bond angles) have been calculated by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set by Gaussian 09 W software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis by using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data, and with the results in the literature. In addition, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies and the other related molecular energy values have been calculated and depicted.

Synthesis of novel 2-(substituted amino)alkylthiopyrimidin-4(3H)-ones as potential antimicrobial agents.

5-Alkyl-6-(substituted benzyl)-2-thiouracils 3a,c were reacted with (2-chloroethyl) diethylamine hydrochloride to afford the corresponding 2-(2-diethylamino)ethylthiopyrimidin- 4(3H)-ones 4a,b. Reaction of 3a-c with N-(2-chloroethyl)pyrrolidine hydrochloride and/or N-(2-chloroethyl)piperidine hydrochloride gave the corresponding 2-[2-(pyrrolidin-1-yl)ethyl]-thiopyrimidin-4(3H)-ones 5a-c and 2-[2-(piperidin-1-yl)ethyl]thiopyrimidin-4(3H)-ones 6a,b, respectively. Treatment of 3a-d with N-(2-chloroethyl)morpholine hydrochloride under the same reaction conditions formed the corresponding 2-[2-(morpholin-4-yl)ethyl]thiopyrimidines 6c-f. On the other hand, 3a,b were reacted with N-(2-bromoethyl)phthalimide and/or N-(3-bromopropyl)phthalimide to furnish the corresponding 2-[2-(N-phthalimido)ethyl]-pyrimidines 7a,b and 2-[3-(N-phthalimido)-propyl]pyrimidines 7c,d, respectively. Compounds 3a-d, 4a,b, 5a-c, 6a-f and 7a-d were screened against Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Bacillus subtilis NRRL 4219 and Bacillus cereus), yeast-like pathogenic fungus (Candida albicans ATCC 10231) and a fungus (Aspergillusniger NRRL 599). The best antibacterial activity was displayed by compounds 3a, 3b, 4a, 5a, 5b, 6d, 6f, 7b and 7d, whereas compounds 4b, 5b, 5c, 6a, 6b and 6f exhibited the best antifungal activity.

2-[(4-Chloro-benz-yl)sulfan-yl]-4-(2-methyl-prop-yl)-6-(phenyl-sulfan-yl)pyrimidine-5-carbonitrile.

In the title compound, C(22)H(20)ClN(3)S(2), the S-bound benzene rings are inclined [dihedral angles = 78.13 (10) and 36.70 (9)°] with respect to the pyrimidine ring. The methyl-propyl group occupies a position normal to the pyrimidine ring [N-C-C-C torsion angle = 92.3 (2)°]. In the crystal, supra-molecular layers are formed in the bc plane, being consolidated by C-H⋯π and π-π inter-actions, the latter between the pyrimidine and S-bound benzene rings [inter-centroid distance = 3.7683 (12) Å].

6-(2-Methyl-prop-yl)-4-oxo-2-sulfanyl-idene-1,2,3,4-tetra-hydro-pyrimidine-5-carbonitrile.

The title thio-uracil derivative, C(9)H(11)N(3)OS, exists in the thione form. The six atoms comprising the ring are almost coplanar [r.m.s. deviation = 0.015 Å] and the 2-methyl-propyl group lies approximately perpendicular to this plane [the N-C-C-C torsion angle is 72.88 (14)°]. Linear supra-molecular chains along [001] sustained by N-H⋯O and N-H⋯S hydrogen bonding feature in the crystal packing.

2-{[(2-Methyl-prop-2-en-1-yl)-oxy]meth-yl}-6-phenyl-2,3,4,5-tetra-hydro-1,2,4-triazine-3,5-dione.

The 1,2,4-triazine ring in the title compound, C(14)H(15)N(3)O(3), is approximately planar (r.m.s. deviation = 0.019 Å); the C atom at the 6-position deviates by 0.026 (2) Šfrom the mean plane whereas the C atom at the 2-position deviates by 0.166 (4) Šin the opposite direction. The triazine ring is oriented at 8.60 (13)° with respect to the phenyl ring. The imino group is hydrogen-bond donor to the exocyclic O atom at the 3-position of an adjacent mol-ecule, the hydrogen bond generating an inversion dimer.

Synthesis and antimicrobial activity of some novel 5-alkyl-6-substituted uracils and related derivatives.

6-chloro-5-ethyl-, n-propyl- and isopropyluracils 5a-c were efficiently prepared from the corresponding 5-alkybarbituric acids 3a-c via treatment with phosphorus oxychloride and N,N-dimethylaniline to yield the corresponding 5-alkyl-2,4,6-trichloro-pyrimidines 4a-c, which were selectively hydrolyzed by heating in 10% aqueous sodium hydroxide for 30 minutes. The reaction of compounds 5a-c with 1-substituted piperazines yielded the corresponding 5-alkyl-6-(4-substituted-1-piperazinyl)uracils 6a-j. The target 8-alkyltetrazolo[1,5-f]pyrimidine-5,7(3H,6H)-diones 7a-c were prepared via the reaction of 5a-c with sodium azide. Compounds 6a-j and 7a-c were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Compound 6h displayed potent broad-spectrum antibacterial activity, while compound 6b showed moderate activity against the Gram-positive bacteria. All the tested compounds were practically inactive against Candida albicans.

2-Benzyl-sulfanyl-4-pentyl-6-(phenyl-sulfan-yl)pyrimidine-5-carbonitrile.

In the title pyrimidine derivative, C(23)H(23)N(3)S(2), the phenyl-sulfanyl and benzyl-sulfanyl benzene rings are orientated away from the carbonitrile group and are twisted out of the plane of the central ring with dihedral angles of 77.66 (6) and 64.73 (5)°, respectively. The n-pentyl group has an extended trans conformation. In the crystal, supra-molecular layers in the ab plane are sustained by C-H⋯π and π-π inter-actions [pyrimidine-phenyl-sulfanyl centroid-centroid distance = 3.8087 (7) Å].