Abstract
The kinetics of the thermal Curtius rearrangement of benzoheteroaroyl azides, i.e., 2-benzofuroyl azide (2), 2-benzothenoyl azide (4), 2-indolecarbonyl azide (6), 2-, 3-, 4-, 5-, 6-, and 7-quinolinecarbonyl azides (8, 10, 12, 13, 14, and 15), and 1- and 2-naphthoyl azides (17 and 18), in toluene were studied by infrared spectrophotometry to determine how the annelation of the benzene ring to side b of 2-furoyl, 2-thenoyl, and 2-pyrrolecarbonyl azides (1, 3, and 5) and 2-, 3-, and 4-pyridinecarbonyl azides (7, 9, and 11) affects the rearrangement and its rate. The annelation effect slightly promotes the rearrangement ; the effect on the thiophene ring and pyrrole ring is greater than that on the furan ring, and the effect on the pyridine ring of 4-pyridinecarbonyl azide (11) is greater than that on the pyridine ring of 2- and 3-pyridinecarbonyl azides (7 and 9).
