Variations in site of lithiation of N-[(2-(4-methoxyphenyl)ethyl)]pivalamide; use in ring substitution

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.

Highly regioselective dinitration of toluene over zeolite H-beta

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.

Technical quality of root fillings performed by undergraduate students in Saudi Arabia

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.

الصفحات

اشترك ب KSU Faculty آر.إس.إس