The microwave synthesis of quinoline alkaloid 4-methoxyquinolin-2(1H)-one 3a and its analogues 3b-e was achieved in 8-11 minutes by methoxydechlorinated of 4-chloroquinolin-2(1H)ones 2a-e using TBAB as phase transfer catalyst. The starting compound obtained by selective decholorination of 1a-e by sodium acetate/acetic acid and the structure of synthesized compound has been established by IR, 1H...

The title compound, C(17)H(13)N(3)OS, was obtained by the reaction of benzoyl chloride, ammonium thio-cyanate and 5-amino-quinoline in the presence of polyethyl-eneglycol-400 (PEG-400) as a phase-transfer catalyst. The compound crystallized as discrete mol-ecules linked by N-H⋯N and C-H⋯N hydrogen bonds involving all the potential donors, generating sheets parallel to (100). An intramolecular N...

An enantioselective Biginelli reaction has been developed by using a bifunctional primary amine-thiourea-TfOH (BPAT·TfOH) as a chiral phase-transfer catalyst and t-BuNH(2)·TFA as an additive in saturated brine at room temperature. The corresponding dihydropyrimidines were obtained in moderate-to-good yields with up to 99% ee under mild conditions. A plausible transition state has been proposed ...

The synthesis of the azoxybenzenes by the reduction of nitroarenes with reducing agent potassium borohydride in water was reported for the first time. PEG-400 was used as a phase transfer catalyst and could effectively catalyze the reduction. The electronic effects of substituent groups play an important role in determining the reduction efficiencies. Electron-withdrawing substituents promote t...

Inverse melting is the phenomenon, observed in both helium isotopes, by which a crystal melts when cooled at constant pressure. I investigate discrete-space analogs of inverse melting by means of two instances of a triangular-lattice-gas system endowed with a soft-core repulsion and a short-ranged attraction. To reconstruct the phase diagram, I use both transfer-matrix and Monte Carlo methods, ...

background: there is no doubt that luteal phase support is essential to enhance the reproductive outcome in ivf cycles. in addition to progesterone and human chorionic gonadotropin, several studies have described gnrh agonists as luteal phase support to improve implantation rate, pregnancy rate and live birth rate, whereas other studies showed dissimilar conclusions. all of these studies have b...

I In this paper a new method for representation of cepstrally smoothed speech spectra by a pole—zero model is presented. In this method the cepatrally smoothed log spectrum is split into two parts, one corresponding to the response of the numerator polynomial of the model transfer function arid the other part to the response of the denominator polynomial of the model transfer function. The deco...