575451-15-9Relevant articles and documents
Safe and reliable synthesis of diazoketones and quinoxalines in a continuous flow reactor
Martin, Laetitia J.,Marzinzik, Andreas L.,Ley, Steven V.,Baxendale, Ian R.
supporting information; experimental part, p. 320 - 323 (2011/03/23)
A flow method for the synthesis of aliphatic and aromatic diazoketones from acyl chloride precursors has been developed and used to prepare quinoxalines in a multistep sequence without isolation of the potentially explosive diazoketone. The protocol showcases an efficient in-line purification using supported scavengers with time-saving and safety benefits and in particular a reduction in the operator's exposure to carcinogenic phenylenediamines.
Nitroxyl radical reactions with 4-pentenyl- and cyclopropylketenes: New routes to 5-hexenyl- and cyclopropylmethyl radicals
Allen,Fenwick,Henry-Riyad,Tidwell
, p. 5759 - 5765 (2007/10/03)
4-Pentenylketenes 4a and 9 and cyclopropylketenes 3a, 13, 14 (RCH=C=O) are generated by photochemical Wolff rearrangements and observed by IR as relatively long-lived species at room temperature in hydrocarbon solvents. The reactions of these ketenes with the nitroxyl radicals tetramethylpiperidinyloxyl (TEMPO, TO?) and tetramethylisoindoline-2-oxyl (TMIO, IO?) form carboxy substituted 5-hexenyl and cyclopropylmethyl radicals which are either trapped by a second nitroxyl radical or undergo rearrangements followed by trapping. The rate constant of the reaction of 4a with TEMPO was similar to that of n-BuCH=C=O (1b), while 3a was 4.3 times more reactive, indicating cyclopropyl stabilization of the incipient radical.
