Valerophenone

Abstract: Urinary metabolites of α-pyrrolidinovalerophenone (α-PVP) in humans were investigated by analyzing urine specimens obtained from abusers Unambiguous identification and accurate quantification of major metabolites were realized using gas chromatography–mass spectrometry and liquid chromatography-tandem mass spectrometry with newly synthesized authentic standards Two major metabolic pathways were revealed: (1) the reduction of the β-keto moiety to 1-phenyl-2-(pyrrolidin-1-yl)pentan-1-ol (OH-α-PVP, diastereomers) partly followed by conjugation to its glucuronide, and (2) the oxidation at the 2″-position of the pyrrolidine ring to α-(2″-oxo-pyrrolidino)valerophenone (2″-oxo-α-PVP) via the putative intermediate α-(2″-hydroxypyrrolidino)valerophenone (2″-OH-α-PVP) Of the metabolites retaining the structural characteristics of the parent drug, OH-α-PVP was most abundant in most of the specimens examined

Abstract: Kinetics and products of the photoreaction of the phenyl ketone valerophenone were investigated as a function of temperature, pH, and wavelength in aqueous solution. Under these conditions (<10-4 M), the photoreactions are pseudo-first-order with respect to valerophenone concentration. Type II quantum yields for photoreaction were close to unity throughout the 290−330 nm spectral region and in the temperature range from 10 to 40 °C. The quantum yields for the photoproducts were 0.65 ± 0.04 for cleavage to acetophenone and propene and an overall yield of 0.32 ± 0.03 for cyclization to two cyclobutanols at 20 °C. A small amount of 1-phenylcyclopentanol (∼2% yield) also was formed. These photoreactions were quenchable by additions of the triplet quenchers sorbic alcohol or sorbic acid, and Stern−Volmer plots were linear up to at least 80% quenching of the photoreactions. On the basis of quenching studies with steady-state irradiations, the triplet lifetime of valerophenone at 20 °C was estimated to be 52 ns,...

Abstract: The photochemical and photophysical behavior or a large number or phenyl alkanones included in zeolites has been investigated. The interior size and shape or the zeolites control the behavior or the triplet ketone as well as that or the 1,4-diradical generated by Norrish type II γ-hydrogen abstraction. A relationship between the size and shape or the reaction cavity and the extent or the restrictions on the triplet ketone and the diradical intermediate has been observed. A model based on the "reaction cavity" concept has been valuable in understanding the unique influence or the zeolite on the reaction course or the type II process.

Abstract: We have previously reported results from the study of an original photochemical reactor consisting of an electrodeless discharge lamp (MWL) placed into the reactor vessel of a microwave oven [P. Klan, J. Literak, M. Hajek, J. Photochem. Photobiol. A: Chemistry 128 (1999) 145]. The microwave field generates ultraviolet irradiation in the lamp at the same time as it interacts with the studied sample, which is therefore affected by a simultaneous UV/VIS and MW irradiation. Here, five different common photoreactions have been investigated in the reactor: Norrish type II reaction of valerophenone and its p-methyl derivative, photo-Fries reaction, photoreduction of acetophenone, photolysis of a phenacyl ester, and a radical nucleophilic substitution of chlorobenzene in methanol. The reaction conversions and product distributions have been studied in terms of the MWL quality and the scale of the experiment. In addition, MW experiments were compared to those using a conventional UV lamp. The electrodeless lamp is presented as a very simple, economic, and efficient tool for photochemistry.