ABSTRACT
The application of the DMSO/SOCl2 system enabled the intramolecular cyclization/chlorination of N,N-disubstituted 2-alkynylanilines, leading to the synthesis of a series of 3-chloroindoles with moderate to good yields. Differing from the previously reported interrupted Pummerer reaction featuring the introduction of SMe moiety, the current approach adopted an alternative pathway that realized the incorporation of chlorine atom to the indole skeleton via a desulfonylative chlorocyclization process.
ABSTRACT
Pyrazole is a five-membered heterocycle bearing two adjacent nitrogen atoms. Both pharmaceutical agents and natural products with pyrazole as a nucleus have exhibited a broad spectrum of biological activities. In the last few decades, more than 40 pyrazole-containing drugs have been approved by the FDA for the treatment of a broad range of clinical conditions including celecoxib (anti-inflammatory), CDPPB (antipsychotic), difenamizole (analgesic), etc. Owing to the unique physicochemical properties of the pyrazole core, pyrazole-containing drugs may exert better pharmacokinetics and pharmacological effects compared with drugs containing similar heterocyclic rings. The purpose of this paper is to provide an overview of all the existing drugs bearing a pyrazole nucleus that have been approved or in clinical trials, involving their pharmacological activities and SAR studies.
ABSTRACT
A series of alkoxylated isobenzofuranones were conveniently synthesized from the reaction of 2-(1-arylvinyl)benzoic acids with PhI(OR)2, generated in situ from the reaction of iodosobenzene (PhIO) with alkyl alcohols. This hypervalent iodine mediated one-pot transformation is postulated to undergo a cascade reaction involving lactonization, 1,2-aryl migration and alkoxylation processes. The organocatalytic and chiral organoiodine-catalyzed asymmetric reactions of the current transformation were also probed.
ABSTRACT
A liquid-level sensing method based on differential pulse-width pair Brillouin optical time-domain analysis (DPP-BOTDA) combining with a self-heated high attenuation fiber (HAF) is proposed, where the principle is to locate the temperature abruption position at the interface between liquid and air caused by their different thermal diffusion rates. A Panda polarization-maintaining fiber is used as the sensing optical fiber, which is tightly glued alongside a laser-powered HAF. Heated by a high-power laser, the temperature of the HAF can increase and exhibits approximately exponential attenuation with the light propagation direction, which induces a similar temperature distribution over the sensing fiber. By using a 5-cm spatial resolution DPP-BOTDA and a 1.4-W heating light, temperature distributions of the sensing fiber are measured for different water levels, and the results indicate that distributed liquid-level sensing with a range of 20 cm and a resolution of 1 cm is realized using our method.
