[title]Photochemistry of diazonium salts. I. Synthesis of 4-fluoroimidazoles, 4-fluorohistamine, and 4-fluorohistidine [author]Kenneth L. Kirk, Louis A. Cohen [journal]J. Am. Chem. Soc., 1973, 95 (14), pp 4619–4624 [link] http://pubs.acs.org/doi/pdf/10.1021/ja00795a026 十分感谢 呵呵