Quinolines rearrangement

Stiasni, N. and Kappe, C.O., A tandem intramolecular Michael-addition/elimination sequence in dihydropy-rimidone to quinoline rearrangements, ARKIVOC, 2002, 71-79. 

Thus it was established that 3-substituted 4-allyl ethers of quinoline rearrange to the nitrogen atom rather than to the benzene ring. 

Scheme 10 Indole-quinoline rearrangement in the biogenesis of cinchoninone.

Sulfonation. The main sulfonation product of quinoline at 220°C is 8-quinoHnesulfonic acid [85-48-3]-, at 300°C it rearranges to 6-quinolinesulfonic acid [65433-95-6] (10). Optimum conditions for sulfonation, 2 h at 140°C and a 1 4 quinoline/40% (wt) oleum ratio, produces 80% yield. The yield drops to 64% at 130°C with a 1 3 reactant ratio (11). Somewhat higher, but variable, yields of 8-quinoHnesulfonic acid hydrochloride [85-48-3] have been reported with chlorosulfonic acid (12). 

Free Electron Molecular Orbital method colour and constitution, 1, 342 Freelingyne occurrence, 4, 706 Free radical processes in photography, 1, 387-389 Friedlander synthesis quinolines, 2, 443 thioindigo dyes, 4, 910 Fries rearrangement chroman-4-one synthesis from, 3, 850 Fructose, 1-deoxy- C NMR, 4, 575 Frusemide as diuretic, 1, 174 metabolism, 1, 245 FS-32 — see 1/f-Indazole, l-[3-... 

Reaction of 1-ethoxycyclohexene (34) with dichlorocarbene gives 1-ethoxy-7,7-dichloronorcarane (35) in 87 % yield. Rearrangement of dichlorocyclo-propane (35) in hot quinoline results in loss of both chlorine atoms to give l-ethoxycyclohepta-l,3,5-triene (37) in 37% yield. Hydrolysis of enol ether (37) with a very small quantity of hydrochloric acid in methanol produces cyclohepta-3,5-dienone (38) in 91 % yield. ... 

The formation of a library of 2-substituted quinolines employed a variation on the Boekelheide reaction. Treatment of A-oxide 41 with isobutylchloroformate did not result in the typical rearrangement. However, subsequent exposure to Grignard reagents resulted in loss of the carbonate with concomitant formation of the 2-substitute derivatives 42. 

Due to the commercial availability of EMME in good purity, there has not been a need to develop new methods to prepare 3-anilino-acrylates therefore, only a few alternatives have been reported. One approach described thermal carbene generation from 37, and rearrangement to form 38. Cyclization in refluxing 1,2-dichlorobenzene (1,2-DCB) provided the 2, 3, 4-trisubstituted quinolines. An electron-withdrawing group (EWG) on the carbene carbon was required for this reaction, and therefore led to the EWG substitution in the 2-position of the quinoline. 

Interest in this reaction was revived when the relevance of a carbene mechanism was realized, particularly following the demonstration (cf. SectionI,B) of a similar ring expansion of indene to 2-chloro-naphthalene by dichlorocarbene via the cyclopropane adduct. Indeed, at this time Nakazaki suggested that these reactions occurred by the addition of dichlorocarbene to the indolyl anion and subsequent rearrangement to the indolenine and, with loss of chloride ion, to the quinoline [Eq. (12)]. The preference of dichlorocarbene for... 

The electron impact positive ion spectrum of l,2,5-oxadiazolo[3,4-/]quinoline IV-oxide 46 shows the loss of N2O2 from the molecular ion, a process that must be followed by a substantial rearrangement to enable the observed loss of propyne-nitrile. This remarkable result apparently arises through a series of H-atom shifts which relocate the dehydroaromatic moiety in the heteroring (890MS465). 

Amino-2-phenyl-2//-benzotriazole reacted with epichlorhydrin in chlorobenzene at 140-145°C to give the A-benzyl-7-hydroxy-6,7,8,9-tetrahydrotriazolo-quinoline derivative 194. This was benzylated and rearranged by heating in DMSO to give the isomeric 7-benzyloxy derivative 195 (Scheme 59) (77MI2). 

Treatment of quinoline 2-thiol derivative 660 with 2,3-dibromopropanol gave the thiazoloquinoline 661 which upon treatment with K2CO3 gave a mixture of 662 and the rearrangement product 663. Separation, hydrolysis and reaction of 662 with A -methylpiperazine afforded 664 (93JMC3148)... 

Rearrangement of oxadiazole bearing quinoline 772 gave the triazolo-quinolinyl ketoxime 773 (93H1577) (Seheme 135). 

It is necessary to hold the reaction temperature below —5° in order to prevent 1,2-rearrangement of the Reissert anion to 1-benzoyliso-quinoline [Isoquinoline, 1-benzoyl-].5... 

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