Organic Communications Articles

One pot reaction of various 2-amino-thiadiazoles or thiazoles and 2,3- dihydrofuran under mild condition in presence of CeCl 3.7H 2O as catalyst transformed the amino group of 2-amino-thiadiazoles or thiazoles into a medicinally important 2-hydroxy pyrrolidine ring system in good to excellent yields. The generality of the reaction was sufficiently investigated and demonstrated. The new reaction path way for this conversion was established by spectroscopic and analytical methods.

Synthesis of a series of a new class of phosphorus macrocycles was accomplished in two steps by condensation of (Z)-2-((2-mercaptophenylimino) methyl) phenol (1) with phosphorus oxychloride (2) in dry THF in the presence of triethylamine at 0-5 °C. In the second step ethylene diols/ amino alcohols/ diamine/ aminothiols/ phenols were reacted at room temperature in THF to afford the title compounds (5a-l). The chemical structures of the title products were characterized by IR, 1H, 13C, 31P-NMR, mass spectral studies and elemental analysis. All the title compounds were evaluated for antimicrobial activity to determine their efficacy and they were found role effective in suppressing the growth of bacteria and fungi.

A new series of 3-thio-1,5-dihydro-2,4,3-benzodioxaphosphepin-3-amino acid esters (4a-k) were synthesized by treating different amino acid ester hydrochlorides (3a-k) with phosphorus monochloride intermediate (2) which was previously formed in situ from 1,2-phenylenedimethanol (1) and thiophosphoryl chloride in the presence of triethylamine in dry tetrahydrofuran (THF) at 0-5 ºC to room temperature. The structures of the title compounds (4a-k) were established by analytical, IR, NMR (1H, 13C and 31P) and mass spectra, and they have been screened for their antimicrobial activity. They exhibited significant antibacterial, and antifungal activity.

A variety of α-bromoketones undergoes smooth condensation with thiourea/ thioamide compounds to afford the corresponding substituted thiazole derivatives in excellent yields. The condensation reactions were carried out in a recyclable reaction medium glycerin without using any catalyst. All the reactions were completed within 2 hours of reaction time at room temperature.