Quinoline, 3-mercapto

F. Quinolines Carrying a Mercapto Group on the Benzo Ring, 400... 

The same diamine, when treated with carbon disulfide in alkaline medium, yielded 2-mercapto- l//-imidazo[4,5-/]quinoline (88PS267,88SC973,86IJC264), which, on treatment with alkyl, aralkyl, and acid halides, gave the corresponding thioethers and thioesters 111, respectively (88PS267, 86IJC264). 

Phenyl-l, 2,3,6-tetrahydro[l, 3]thiazino[3,2-n]quinolin-6-ones 90 were prepared in the reactions of 2-mercapto-5-phenyl-l,4-dihydroquinolin-4-ones 103 and 1,3-dihalopropane in 55-79% yields (97JAP(K)97/278780). 

Quinoline, 8-mercapto-2-methyl-metal complexes, 2, 800 Quinoline, 2-methyl-8-(methylthio)-metal complexes, 2,801 Quinoline, 8-methylthio-metal complexes, 2, 801 Quinoline-2-carboxylic-acid, 8-hydroxy-methyl ester... 

Phenyl-l,2,3,6-tetrahydropyrido[2,l- ][l,3]thiazino[3,2- ]quinolin-6-ones were prepared by the reaction of 2-mercapto-5-phenyl-l,4-dihydroquinolin-4-ones with 1,3-dihalopropane <1997JAK97/278780>. 7-Acetyl-2-aryl-9-cyano-6-methyl-8-phenyl-3,4-dihydro-277,877-pyrido[2,l- ][l,3]thiazin-4-ones were obtained from 5-acetyl-3-cyano-6-methyl-4-phenyl-l,2,3,4-tetrahydropyridine-2-thione with 3-aryl-2-propenoyl chloride <2002CHE761>. Reaction... 

Another synthetic approach to the octahedral complexes of type (252) is provided by the thermal decomposition of the hydrido complex [ReH7(PPh3)2] in the presence of 2-mercapto-quinoline or 2-hydroxyquinoline in 1,2-dichloroethane solutions. The solvent is source of the chloro ligands and, thus, essential for the formation of the rhenium(III) products. Comparable reactions in THF afford hydridorhenium(V) complexes (see Section 5.3.2.11). 

UV and pKa measurements show that pyridine-3-thiol and quinoline-3-thiol occur predominantly in the zwitterion form, e.g. (133) (76AHC(S1)144). Quinolines carrying a mercapto group on the benzo ring exist in the zwitterion or the zwitterion extended quinone form to a larger extent than do the analogous hydroxy compounds (63AHC(S1)400). 

Protonation of pyridinethiones and quinoline-4-thione occurs at sulfur, giving the corresponding mercapto-pyridinium and -quinolinium cations (65JCS3825, 62JCS3127). 

MI4 95CCR313), 8-hydroxy(mercapto)quinolines (50), azomethines (51) and (52) (93MI5 96MI14), and formazanes (53) (91KK1011 96MI12). 

Quinaldohydroxamic acid as metal precipitant, 506 Quinodimethane, tetracyano-metal complexes, 263 Quinoline, 8-(alkylthio)-metal complexes, 801 Quinoline, 8-hydroxy-metal complexes, 795 Quinoline, 8-hydroxy-2-methyl-cobalt(II) complexes, 795 Quinoline, 8-mercapto-metal complexes, 800 Quinoline, 8-mercapto-2-methyl-metal complexes, 800 Quinoline, 2-methyl-8-(methylthio)-metal complexes, 801 Quinoline, 8-methylthio-metal complexes, 801 8-Quinolineselenol metal complexes, 807 Quinones... 

Certain aromatic imines undergo a similar cyclodehydrogenation to the phenanthridine. Benzylideneaniline (330) yields phenanthridine (331) only in sulfuric acid,355 whereas diphenylmethyleneaniline cyclizes in the presence of oxygen or iodine.356 Cyclizations have also been reported in Schiff s bases formed from a- and /J-naphthylamine357 and from 4-aminoquinoline,358 and in the mesomeric betaine 4,5-diphenyl-2-mercapto-l,3,4-thiadiazolium hydroxide.359 Irradiation of the anil of 2-aminonaphthalene (332) in ethanol, however, leads to incorporation of ethanol and the formation of 3-phenylbenzo[/]-quinoline (333).860 Additional photoproducts are obtained when the photolysis is carried out in w-hexanol.361... 

The 1,1-dioxide of 3-halomethyl-2,3-dihydropyrido[l,2,3-de]-l,4-benzo-thiazinium triiodide and bromide were prepared by cyclization of 8-allyl-sulfonylquinoline with I2 in 2-PrOH, and with Br2 in CHCI3 (93MI9). When 8-[(l-chloro-2-mercapto-2-propyl)thio]quinoline HC1 was left to stand in EtOH at 20°C 2-mercapto-2-methyl-2,3-dihydropyrido[l,2,3-de]-l,4-benzothiazinium chloride was obtained (94ZOR636). 8-[2-Chloro-l-(un)-substituted ethylthio]quinolines could easily cyclized to 2,3-dihydropyrido-... 

Carbon-sulfur bond formation by oxidative cyclization of a thiourea derivative using bromine will in the case of (521) furnish a thiazolo[/,/]quinoline (522 Z = NH). The same imine is obtained from 8-mercapto-l,2,3,4-tetrahydroquinoline on treatment with cyanogen bromide with phosgene the 2-oxo derivative (522 Z = 0) is formed (63JOC2581). 

Mercapto-2-substituted quinolines, structure and properties of chelates 90MI37. 

Examples of ring closures with c-amino mercapto heterocyclic compounds are the reactions of carbon disulfide with o-amino mercapto pyridines and o-amino mercapto quinolines, which respectively yield dihydrothiazolo pyridine-2-thiones and dihydrothiazolo qumohne-2-thiones. A summary of these compounds are 7 ... 

Ainino raercapto pyridine Aniino mercapto quinoline... 

Pyrazolo[3,4-Z)]pyridines, the 7-chloro-6-fluoro-2,4-dimethylquinoline and its mercapto-thiadiazolyl or oxadiazolyl quinolines 21 were prepared via Diels-Alder reaction conversion of methyl 2-(3-oxo-3-phenylpropenylamino)benzoate into 3-benzoyl-l.S -quinolin-4-one 22 . A mixture of aniline derivatives and malonic ester gave a variety of 3-aryl-4-hydroxyquinolin-2(l//)-ones 23. Condensation of isatins with ketones afforded quinoline-4-carboxylic acids. 2-Aryl-l,2,3,4-tetrahydro-4-quinolinones 22 and carbazolylquinolone were also prepared. The substitution of 2-chloroquinoline gave the 2-substituted quinolines. Basic alumina has catalyzed the C-C bond formation between 2-hydroxy-1,4-naphthoquinone and 2-chloroquinoline derivative to give 21. Reaction of organic halides with 8-hydroxyquinolines gave the respective ethers. The azodye derivatives of 21 were prepared in the absence of solvent. Silica gel catalyzed the formation of 2-ketomethylquinolines from reaction of 2-methylquinolines with acyl chlorides. 

The chlorine atom of 4-(2-chloroacetyl)pyrazol-3-ones 285a-c was displaced relatively easily by 2-mercapto-37/-quinolin-4-ones 286a c in boiling acetone containing potassium carbonate to afford the 4-substituted pyrazol-3-ones 287a-c in good yields (90AP623) (Scheme 76). 

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