22264-09-1Relevant academic research and scientific papers
Protecting Groups for the Synthesis of Diaza-cyclophanes by the Rigid-Group Principle
Funke, Ulrike,Gruetzmacher, Hans-Friedrich
, p. 1503 - 1508 (2007/10/02)
4,4-Dimethyl-1,2-bis(4-methylphenyl)-3,5-pyrazolidinedione (4), 1,2-bis(4-methylphenyl)perhydro-3,6-pyridazinedione (5), and 1,2-bis(4-methylphenyl)perhydro-3,7-diazepinedione (6) have been prepared by condensation of p-hydrazotoluene with the appropriate dicarbonyl dichlorides and then converted into the corresponding bis(bromomethyl) derivatives 7-9 by photobromination. 7-9 have been tested as starting compounds for the synthesis of 2-thia-10,11-diazaparacyclophan-10-ene (2) and 2,5-dithia-13,14-diazaparacyclophan-13-en (3).In no case 2 has been obtained, independent of the ring size and conformation of 7-9.However, 3 was readily formed from all precursors; the dimethylmalonyl moiety proved to be convenient as a protecting group because of its ease of preparation, its stability, and its facile cleavage by alkali. - Keywords: Diazacyclophan-enes / Rigid-group principle
