The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Catalytic synthesis of 2-alkylbenzoxazoles》. Authors are Kozlov, N. S.; Kiselev, B. I..The article about the compound:2-Ethylbenzo[d]oxazolecas:6797-13-3,SMILESS:CCC1=NC2=CC=CC=C2O1).Reference of 2-Ethylbenzo[d]oxazole. Through the article, more information about this compound (cas:6797-13-3) is conveyed.
A mixture of 0.1 mole o-nitrophenol and 0.3 mole ROH( R = alkyl) was passed at the rate of 20 g./hr. over Cu-Al2O3 catalyst kept at 300-10°, unreacted material distilled and the residue worked up with alkali, washed with H2O, and dried to yield 2-alkylbenzoxazoles (R, b.p./mm., d20, n20D, and % yield given): H, 180-2°/760, -,-, 20; Me, 201°/760, 1.12, 1.5531, 31; Et, 98-9°/10, 1.0879, 1.5420, 34; Pr, 116-18°/10, 1.066, 1.5338, 69; iso-Pr, 109-11°/10, 1.0799, 1.5391, 32; Bu, 133-5°/10, 1.042, 1.5271, 21; iso-Bu, 120-2°/10, 1.028, 1.5090, 15; C5H11, 145-7°/10, 1.0072, 1.5173, 30; C6H13, 164-5°/10, 0.983, 1.5000, 25; C7H15, 176-8°/10, 0.943, 1.4818, 30; C8H17 (m. 26°), -, -, 27; and C9H19, (m. 22-3°), -, -, 20. Ir spectra are discussed.
Different reactions of this compound(2-Ethylbenzo[d]oxazole)Reference of 2-Ethylbenzo[d]oxazole require different conditions, so the reaction conditions are very important.
Reference:
Benzoxazole – Wikipedia,
Benzoxazole | C7H5NO – PubChem