ZrCl4 or ZrOCl2 under neat conditions: optimized green alternatives for the Biginelli reaction

Development of Novel Thiazolopyrimidines as CDC25B Phosphatase Inhibitors

“…The 3,5-dibromo-4-hydroxyphenyl derivative 44, which is the most potent CDC25 inhibitor, also displayed the best cytotoxic potency against LNCaP, with an IC 50 value of 3.4 mm, but was observed to be inactive against MiaPaCa-2. Several other potent in vitro inhibitors including 31,32,45,48,53,54,58,63,64, and 71 shared the same profile. In contrast, no compound appeared to be selective toward MiaPaCa-2.…”

“…The resulting aqueous phase was extracted with EtOAc after acidification with HCl (1 n). The combined organic layers were washed with brine, dried over Na 2 SO 4 Ethyl-6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (9): [47] According to procedure 1, compound 9 was obtained as a white powder (78 %); mp: 210 8C; Ethyl-4-(3,4-dimethoxphenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (10): [48] Ethyl-4-(3,4-dichlorophenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (11): [49] Ethyl-4-(4-hydroxyphenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (13): [51] According to procedure 1, compound 13 was obtained as a white powder (65 %); mp: 202 8C; 17.7, 54.8, 60.0, 101.0, 125.3, 125.4, 126.6, 126.9, 128.0, 128.4 Ethyl-6-methyl-4-(3,4,5-trimethoxyphenyl)-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (18): [52] (32): According to procedure 3, compound 32 was obtained as a yellow powder (37 %); mp: 238 8C; (59): [54] According to procedure 4, compound 59 was obtained as a yellow powder (27 % Ethyl-(2Z)-5-(3,4-dichlorophenyl)-2-(4-hydroxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H- [1,3]thiazoloA C H T U N G T R E N N U N G [3,2-a]pyrimidine-6-carboxylate (63): According to procedure 3, compound 63 was obtained as a yellow powder (44 %); mp: > 250 8C;…”

Air‐stable zirconium (IV)‐salophen perfluorooctanesulfonate as a highly efficient and reusable catalyst for the synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones/thiones under solvent‐free conditions

“…In show the merit of the present study, the results of using complex 1 for the synthesis of product 5a by reacting benzaldehyde, ethyl acetoacetate, and urea with other homogeneous and heterogeneous catalysts were compared ( Table 4, entries [3][4][5][6][7][8][9][10][11][12][13][14]. According to the obtained results [7,9,13,24,27,[31][32][33][53][54][55] our catalyst shows better catalytic activity with a shorter reaction time using solvent-free conditions with good recyclability. Apparently, the long fluoroalkyl chain in the sulfonate must be responsible for the hydrophobicity and increasing the catalytic activity.…”

Applications of Zirconium (IV) Compounds in Organic Synthesis

“…The three component reaction of aldehyde, ethyl acetoacetate and urea in the presence of 10 mol% zirconium(IV) chloride in refluxing ethanol proceeded smoothly and rapidly to give the corresponding dihydropyrimidinone in high yield (Scheme 36). This reaction can also performed using ZrCl 4 or ZrOCl 2 ·8H 2 O under neat conditions [84,85] or ultrasonic conditions [86].…”