Lithiation of N-(2-(4-methoxyphenyl)ethyl)pivalamide at -20 to 0 °C with three mole equivalents of n-BuLi in anhydrous THF, followed by reactions with various electrophiles, gives high yields of products involving ring substitution ortho- to the pivaloylaminoethyl group, which was unexpected in view of earlier results reported with t-BuLi.

A nitration system comprising nitric acid, propanoic anhydride and zeolite Hb has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6‑dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4‑dinitration of toluene; the catalyst is re-usable, solvent is not needed and an aqueous work-up is not required.

Aim To evaluate the technical quality of root fillings performed in the undergraduate clinic of the Dental College, King Saud University, Saudi Arabia and to compare the technical quality of root canal treatment between the 4th- and 5th-year students.

In the challenge of observing precious periodic patterns in the financial time series based on physical time changes, we propose intrinsic time as an alternative to physical time, where events of different magnitudes are the time-scale of the time series. This alternative approach, called directional-change events, defines the time series by the irregularity of time intervals between two sequential events. We believe directional-change events can enhance our study of the financial time series and improve the quality of time series analysis.