195609-20-2Relevant academic research and scientific papers
(±)-1,2-dialkyl-5-nitro-2,3-dihydro-1H-indoles by a tandem reductive amination-SNAr reaction
Bunce, Richard A.,Nago, Takahiro,White, Brian
experimental part, p. 629 - 634 (2009/11/30)
(Chemical Equation Presented) A tandem reductive amination-SNAr reaction has been applied to the synthesis of (±)-1,2-dialkyl-5-nitro-2, 3-dihydro-1H-indoles. Treatment of a series of 2-fluoro-5-nitrobenzyl ketones with primary amines and sodium cyanoborohydride in methanol at room temperature provided good yields of the target heterocycles. The reaction is sensitive to steric hindrance and proceeds best with less hindered ketone substrates using primary amines that are unbranched at the α carbon.
Approaches to 1,1-disubstituted cinnolin-3-ylio oxides: Synthesis and reactivity of a new class of heterocyclic betaines
Aran, Vicente J.,Asensio, Juan L.,Molina, Jose,Munoz, Pilar,Ruiz, Jose R.,Stud, Manfred
, p. 2229 - 2235 (2007/10/03)
The cinnolin-3-ylio oxides 6, a new class of heterocyclic aminimide, can be prepared by intramolecular cyclization of the N′,N′-disubstituted (2-fluorophenyl)acetohydrazides 5. Attempts to prepare these betaines by an alternative route, namely cyclization of the nitrenes expected from the thermal decomposition of (2-dialkylaminophenyl)acetyl azides 11, failed, Curtius rearrangement-derived compounds being the main products isolated from these processes. Hydrochlorides of the cinnolin-3-ylio oxides 6 undergo alkyl halide elimination to yield the 1-(ω-chloroalkyl)cinnolin-3-ols 19a,b or 1-methylcinnolin-3-ol 21. Oxidation of the latter to the 3-hydroxycinnolin-4-one 22, its methylation to the corresponding N1,O-23 and N1,N2-dimethyl 24 derivatives as well as the cyclization of 1-(5-chloropentyl)cinnolin-3-ol 19a to the diazepino[1,2-a]cinnolinone 20 are also reported.
