Synthesis of Some New 1,2,3,4-Tetrahydropyrimidine-2- thiones and Their Thiazolo[3,2-a]pyrimidine Derivatives as Potential Biological Agents

Synthesis and biological evaluation of thiazolo and imidazo N-(4-nitrophenyl)-7-methyl-5-aryl-pyrimidine-6 carboxamide derivatives

“…General procedure for synthesis of substituted N-(4-nitrophenyl)-6-methyl-4-phenyl-2-thioxo/imino-1,2,3,4-tetrahydropyrimidine-5-carboxamide derivatives (6a-g)(8a-g) [16] A mixture of N-(4-nitrophenyl)-3-oxobutamide (0.01 mol), different aromatic aldehyde (0.01 mol), guanidine/thiourea (0.01 mol), and ethanol (8 ml), containing 0.4 ml of concentrated HCl was heated under reflux for 6-8 h. The solution was deep frozen overnight and precipitates were obtained.…”

“…General procedure for synthesis of 5-substituted N-(4-nitrophenyl)-7-methyl-3,5-dihydro-2H-imidazo/thiazolo [3,2-a]pyrimidine-6-carboxamide derivatives (7a-g)(9a-g) [16] 1,2-dichloroethane (0.01 mol) was added to a boiling solution of substituted N-(4-nitrophenyl)-6-methyl-4-phenyl-2-thioxo/imino-1,2,3,4-tetrahydropyrimidine-5-carboxamide derivatives (0.01 mol) in dimethyl formamide and then refluxed for 1 h. After completion of the reaction, the contents were poured on crushed ice. The precipitates obtained were filtered, dried, and recrystallized from ethanol.…”

“…General procedure for synthesis of 5-(2-hydroxynaphthalen-1-yl)-7-methyl-N-(4-nitrophenyl)-3,5-dihydro-2H-thiazolo/imidazo[3,2-a]pyrimidine-6-carboxamide (7f, 9h) [16] A mixture of N-(4-nitrophenyl)-3-oxobutamide (0.01 mol), 2-hydroxynaphthaldehyde (0.01 mol), guanidine/thiourea (0.01 mol), and ethanol (8 ml), containing 0.4 ml of concentrated HCl was heated under reflux for 6-8 h. The solution was deep frozen overnight and precipitates were obtained. 1,2-dichloroethane (0.01 mol) was added to a boiling solution of intermediate obtained above (0.01 mol) in dimethyl formamide and then refluxed for 1 h. After completion of the reaction, the contents were poured on crushed ice.…”

“…Mass spectra were taken on a Bruker Compass Data Analysis 4.0 mass spectrometer. Procedure for synthesis of N-(4-nitrophenyl)-3-oxobutamide (3) [16] A mixture of ethylacetoacetate (0.01 mol) and 4-nitro aniline (0.01 mol) in toluene containing catalytic amount (0.05 ml, 40 %) of NaOH was refluxed on oil bath for 8 h. After completion of the reaction (TLC monitoring), the reaction mixture was kept overnight; separated solid was filtered, washed with petroleum ether and recrystallized from ethanol to obtain N-(4-nitrophenyl)-3-oxobutamide.…”

Design, synthesis, and biological evaluation of thiourea and guanidine derivatives of pyrimidine-6-carboxylate

“…Infra-red (IR) analysis was performed on a SHIMAZDU FT-IR instrument using KBr pellets and was recorded in cm -1 . 1 H NMR spectra were determined using a Bruker DRX-300 FTNMR spectrometer using DMSO-d 6 General procedure for the synthesis of methyl 7-methyl-5-(3,4,5-trimethoxyphenyl)-3,5-dihydro-2H substituted [3,2-a]pyrimidine-6-carboxylate (5a-h) (7a-h) [19] To a boiling solution of intermediate obtained in the above step (0.01 mol) (4a-s) and (6a-s) 1,2-dicholroethane (0.01 mol) was added in dimethyl formamide (5 ml) and then refluxed for 45 min. The solution was poured on crushed ice and the precipitates formed were separated.…”