7CHAUDHARI R V, DIVEHER S S, VAIDYA M J, et al. Single step process for the prepration of p-aminophenol: US 6028227[P]. 2000.
8ZHU H P, YANG F, TANG J, et al. Bronsted acidic ionic liquid 1 methylimidazolium tetrafluoroborate: A green catalyst and recyclablemedium for esterification [J]. Green Chem, 2003, 5(1):38-39.
9COLE A C, JENSEN J L, NTAI I, et al. Novel Bronsted acidic ionicliquids and their use as dual solventcatalysts[J]. J Am Chem Soc, 2002, 124(21): 5962- 5963.
10XING H B, WANG T, ZHOU Z H, et al. The sulfonic acid-functionalized ionic liquids with pyridinium cations: Acidities and their acidity catalytic activity relationships [J]. Journal of Molecular Catalysis A: Chemical, 2007, 264(1-2):53-59.
