N‐methyl chemical shifts in quaternized azoles, isazoles, diazoles, and their benzologs

Abstract

The N‐methyl chemical shifts in the title compounds arc reported. In the 1,3‐orientation, the shift appears to be determined by resonance from the heteroatom, with the order of donating ability being NMe > O > S ˜ Se. In the 1,2‐orientation, electronegativity effects are also important as evidenced by a general downfield shift, and the order of donation is NMe > S ˜ Se > O.

Oxazole chemistry. A review of recent advances

“…Ar = 2-indolyl, l-methyl-2-indolyl, 2-pyridyl, 5-chloro-2pyridyl, 1-quinolinyl, 2-pyrimidyl, 2-thiazolyl, 2-benzimidazolyl, 2-benzothiazolyl, 5-tetrazolyl 2-Acylaminoacids 240 cyclize to the 5-aminooxazoles242 …”