No abstract

(+)−(R)-1-[(E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)acryloyl]-2-piperidine ethanol (FK453) is a novel, potent adenosine A1 receptor antagonist for the regulation of renal function. The development of a reliable process suitable for large scale manufacture is described. A Horner−Emmons reaction and a 1,3-dipolar cycloaddition were successfully scaled up to afford ethyl (E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)acryloylate, with excellent regioselectivity and stereoselectivity. Process improvements and optimization of each step permitted elimination of column chromatography, resulting in a straightforward, practical synthesis of FK453.

Yubari coal is efficiently anionized by sodium metal in hexamethylphosphoric triamide (HMPA) under ultrasonic irradiation at ambient temperature. An ethylated coal prepared from the anionized coal and ethyl iodide shows 90 wt% of solubility in benzene. The improved method solves problems of the conventional Sternberg method of reductive alkylation of coal.

Through an empirical analysis of transfer enthalpies in acetonitrile-methanol mixtures using ten quaternary ammonium ions, an equation which expresses the behaviour of the transfer enthalpy as a function of solvent composition has been derived: AH,A""'"(RR',N+) = AH,AN+mix[(B~')4N+] + 6, AH,AN +MeoH (RR;N+)x,,,, + A(RRjN+)x,,,, xAN.On the basis of this equation it is suggested that the transfer enthalpy includes at least three types of interaction, a protophobic interaction, an electrostatic interaction and another interaction, presumably a specific interaction such as dipole-dipole or acid-base association.

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