Spiro[3H‐pyrazole‐3,3′‐oxindoles] Derived from 1,2,3,4‐Tetrahydroquinoline

Abstract

Aldol condensation of 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione with aryl methyl ketones generates 3‐(aroylmethylidene)oxindoles, which react with hydrazine to generate tricyclic spiro[3H‐pyrazole‐3,3′‐oxindoles].

Spiro[4H‐2,3‐dihydropyran‐3,3′‐oxindoles] derived from 1,2,3,4‐tetrahydroquinoline

“…The starting tricyclic isatin, 5,6‐dihydro‐4 H ‐pyrrolo[3,2,1‐ ij ]quinoline‐1,2‐dione ( 3 ), was prepared following a literature procedure in which 1,2,3,4‐tetrahydroquinoline was reacted with oxalyl chloride and the resulting amide‐acid chloride cyclized by treatment with aluminum chloride. Reaction of amido‐ketone 3 was initially attempted following the earlier three‐component protocol by heating together 5,5‐dimethylcyclohexane‐1,3‐dione (dimedone) 11b , a cyanomethyl aryl ketone 9 , and 4‐( N,N ‐dimethylamino)pyridine (DMAP) in refluxing ethanol.…”

“…We have reported several investigations of the synthesis of spiro‐oxindoles starting from the tricyclic isatin 3 , 5,6‐dihydro‐4 H ‐pyrrolo[3,2,1‐ ij ]quinoline‐1,2‐dione . No previous work had employed 3 until our investigations that showed “normal” isatin behavior in conversions that produced spirocyclic products exemplified in Figure , 4 – 6 .…”

Hexahydrospiro‐pyrazolo[3,4‐b]pyridine‐4,1′‐pyrrolo[3,2,1‐ij]quinolines Derived from 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione

“…We have been examining the chemistry of 5,6‐dihydro‐4 H ‐pyrrolo[3,2,1‐ ij ]quinoline‐1,2‐dione ( 1 ), a tricyclic analogue of isatin (1 H –indole‐2,3‐dione), in which the reactivity of the ketone carbonyl group of the 2‐keto‐amide unit was utilized. Thus, we were able to construct sundry spiro[3,3′‐oxindoles] via three‐component combinations in which, in each case, an initial condensation of the reactive carbonyl group of 1 with an active methylene of the second component, was followed by addition of a nucleophilic third component and finally a cyclizing condensation to generate a spirocyclic heterocyclic ring . As a typical example, condensation of 1 with malononitrile generates the alkene 2 to which the enolate of cyclohexane‐1,3‐dione then adds to generate a species 3 which then ring closes (arrows on 3 ) to give final product 4 (Scheme ) .…”

Spiro[pyrido[3,2,1‐ij]pyrimido[4,5‐b]quinoline‐7,5′‐pyrrolo[2,3‐d]pyrimidines] and Spiro[pyrimido[4,5‐b]quinoline‐5,1′‐pyrrolo[3,2,1‐ij]quinolines] Derived from 5,6‐Dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione

“…We were able to construct sundry spiro [3,3 0 -oxindoles] 2-4 ( Fig. 1) [1][2][3]. Spiro[3,3 0 -oxindoles] based on isatin and derivatives thereof are of continuing chemical and biological interest as attested by two extensive 2014 reviews [4,5] and many recent publications [6].…”

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Spiro[pyrido[3,2,pyrimido [4,5-b] Reaction of 5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinoline-1,2-dione (1) with two equivalents of some 6-aminouracils (or 6-amino-2-thiouracil) generates spirocyclic tetrahydrobenzo[if]quinolizines (7). The one-pot, three-component reaction of amido ketone (1) with 6-aminouracil (or 6-amino-2-thiouracil) and a cyclic six-membered 1,3-diketone produces spirocyclic tetrahydropyrrolo[3,2,1-ij]quinolinones (15).

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