Abstract
The rate of oxime formation of 2-furfural and 5-substituted-2-furfurals such as 5-methyl-2-furfural, 5-isopropyl-2-furfural, 5-tert-butyl-2-furfural, 5-isoamyl-2-furfural and 5-nitro-2-furfural have been measured at 15∼$45^{\circ}C$ in aqueous solution buffered at pH 7. Oxime formation for all the compounds investigated is second-order reaction and their activation energies observed are 5.50, 7.22, 7.03, 7.49, 7.78 and 4.97 kcal/mole, respectively. Hammett equation is obtained for 5-alkyl-2-furfurals and the reaction constants (${\rho}$) calculated at 15, 25, 35 and $45^{\circ}C$ are 2.010, 1.756, 1.541, and 1.311 respectively.
2-푸르푸랄과 5-알킬-2-푸르푸랄류 가운데 5-메틸-2-푸르푸랄, 5-이소프로필-2-푸르푸랄, 5-삼차부틸-2-푸르푸랄, 5-이소아밀-2-푸르푸랄, 그리고 5-니트로-2-푸르푸랄 등의 옥심 생성반응 속도 정수를 pH 7인 완충용액내 반응온도 15∼$45^{\circ}C$에서 구하였다. 이 반응은 2차반응이며 활성화 에너지는 각각 5.50, 7.22, 7.03, 7.49, 7.78 그리고 4.97 kcal/mole이다. 5-알킬-2-푸르푸랄류에 대하여는 Hammett식이 성립되고 반응온도 15, 25, 35, $45^{\circ}C$에서 반응정수는 각각 2.010, 1.756, 1.541, 1.311 등이 계산되었다.