5-Butyl-3-ethyl-4,5-dihydro

Isoquinoline, butyl-Isoquinoline, 1-butyl-Isoquinoline, dihydro-Isoquinoline, dihydroethyl-Isoquinoline, dihydromethyl-Isoquinoline, dimethyl-Isoquinoline, ethyl-... 

Benzopyran-3-one, l,4-dihydro-6,7-dimethoxy-], 55, 45 Isocyamde, benzyl-, 55, 98 Isocyanide, butyl-, 55, 98 ISOCYANIDE, tert-butyl- [Isocyamde, 1,1-dimethylethyl-], 55, 96 Isocyamde, cyclohexyl-, 55, 98 Isocyamde, dodecanyl-, 55, 98 Isocyamde, ethyl, 55,98 Isocyamde, methyl, 55, 98 Isocyamde, phenyl-, 55, 98 (-)-2,3 4,6-Di-0-isopropylidene-2-keto-L-gulomc acid, hydrate [L-jcy/o-2-Hex-ulosomc acid, bis-<9-( 1 -mcthylcthyl-ldene)-], 55,80, 81 ISOXAZOl F, 3-(4-chlorophenv1)-5-(4-methoxyphenyl)-, 55, 39 Isoxazole,5 -(4-chloropheny l)-3-(4-me th-oxyphenyl)-, 55,42... 

Methylbutyl acetate, see sec-Amyl acetate 3-Methylbutyl acetate, see Isoamyl acetate 3-Methyl-l-butyl acetate, see Isoamyl acetate 3-Methylbutyl ethanoate, see Isoamyl acetate Methylbutyl ethyl ketone, see 5-Methyl-3-heptanone Methyl n-butyl ketone, see 2-Hexanone Methylcarbamate-l-naphthalenol, see Carbaryl Methylcarbamate-l -naphthol, see Carbaryl Methyl carbamic acid, 2,3-dihydro-2,2-dimethyl-7-... 

The mechanism of the acid-catalyzed decomposition of 1-alkyltriazolines has been studied <93JOC2097>. The hydrolytic decomposition of these triazolines in aqueous buffers leads predominantly to 1-alkylaziridines with lesser amounts of 2-(alkylamino)ethanol, alkylamines, and acetaldehyde. The rate of hydrolysis of 1-alkyltriazolines is about twice as fast as that of the analogous acyclic 1,3,3-trialkyltriazenes and varies in the order t-butyl > isopropyl > ethyl > butyl > methyl > propyl > benzyl <92JOC6448>. The proposed mechanism, involving rate-limiting formation of a 2-(alkylamino)ethyldiazonium ion, is shown in Scheme 65. A theoretical study ab initio calculation) of the acid-induced decomposition of 4,5-dihydro-l,2,3-triazolines has also been reported <91JA7893>. 

The synthesis of the [2.3.4]cyclazine derivatives (301) and (186) has been described in Section 3.08.6.3.2 (Scheme 24). It has been shown in Section 3.08.6.1.3 that attempts to synthesize 9-aza[2.3.4]cyclazine (302) yielded the 8,9-dihydro derivatives (146), which may have been formed by reduction of the intermediate cyclazine. Attempts to remove the ester groups of (301) and (186) by hydrolysis of the ethyl ester and subsequent thermal decarboxylation or by thermolysis of the f-butyl ester failed. The reaction of (301) with LAH led to decomposition. The preparation of a dihydro[2.3.4]cyclazine derivative (89) has been described in Section 3.08.3.5. It has been pointed out that an attempted elimination of HCN, to give the fully conjugated cyclazine, failed. 

The enaminone from ethyl acetoacetate and t- butyl 2-aminocyanoacetate (80) reacts with ethyl acrylate under basic conditions to give the pyrrolopyridine (81). The dihydro derivative (82) is aromatized by mild oxidation (Scheme 28) (78CPB3080). 

A peroxy acid mediated oxidative rearrangement of 2-alkoxy-3,4-dihydro-2//- pyrans affords 5-alkoxytetrahydrofuran-2-carbaldehydes (79JCS(Pi)847>. This reaction pathway was used in developing a method for the synthesis of optically active monoalkylfurans. (S)-2-Ethoxy-5-s-butyl-3,4-dihydro-2//-pyran (319), obtained through a cycloaddition reaction of (S)-2-s-butylacrolein to ethyl vinyl ether, was converted to (S)-2-s-butyl-5-ethoxytetrahydrofuran-2-carbaldehyde (320) (Scheme 85). 

The last one (6.2 g, 18.4 mmol) was converted into 3,4-dihydro-4-hydroxy-2-(2-methoxy)ethyl-2H-thieno[3,2-e]-l,2-thiazine-6-sulfonamide 1,1-dioxide (4.87 g, 77%) m.p. 187°C by using the reaction with n-butyl lithium in anhydrous THF at -40°C for 40 min, and then bubbling sulfur dioxide gas for 20 min after which time the mixture was warmed to room temperature. After 30 min at room temperature the mixture was concentrated the residue was dissolved in water, cooled (0°C), sodium acetate trihydrate was added followed by hydroxylamine-O-sulfonic acid. The reaction mixture was stirred at room temperature for 18 h after which time was basified with solid sodium bicarbonate and extracted with ethyl acetate. 

A solution of 1 eq. of the tert-butyl ester of 7-aminocephalosporanic acid and 1 eq. of dicyclohexylcarbodiimide in 100 ml of methylene chloride/DMF (1 1) is cooled to 0°C. The mixture is combined with 1 eq. of 3,5-dichloro-4-pyridone-l-acetic acid after 5 min the ice bath is removed and the mixture agitated for another 30 min at 25°C. The thus-formed urea is filtered off and the filtrate filtered over silica gel (eluent ethyl acetate/1% methanol). The solvent is concentrated by evaporation, and the thus-obtained tert-butyl ester of 7-(3,5-dichloro-l,4-dihydro-4-oxo-l-pyridylacetamido)cephalosporanic acid is crystallized from ether. 

Butyl-1,6-naphthyridine 7-Butyl-8-phenylseleno-1,6-naphthyridine 7-Butyl-8-phenylthio-1,6-naphthyridine 7-Butylthio- l-ethyl-4-oxo-1,4-dihydro-1,... 

Ethyl l-terf-butyl-7-chloro-6-fluoro-5-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate 178, NMR 454... 

Intramolecular nucleophilic cyclization is used for the synthesis of four-membered heterocycles. This is a general route for reactions of many perfluoroolefins with primary amines. Thus the interaction between perfhioro-3,4-dimethylhex-3-ene and butylamine in the presence of triethylamine forms N-butyl-perfhioro-2,3,4-trimethyl-2-ethyl-l, 2-dihydro-azete (87ASCC31). In the absence of triethylamine, a mixture of products is obtained, among which are the derivatives of azetidine 15 and azete 16. 

Aryloxy-2,3-dihydro- -2-oxid E2, 514 2-Butyl-2,3-dihydro- -2-oxid Xll/l, 535 5-Chlor-2-mercapto-2,3-dihydro- -2-sulfid-Pyri-dinium-Salz E2, 767 2-(2-Cyan-ethyl)-2-ethoxy- E2, 481 2-Cyclohexyl-2,3-dihydro- -2-oxid XII/I, 535 2-Ethoxy-2,3-dihydro- E2, 481 2-Ethoxy-2-(2-methoxycarbonyl-ethyl)- E2, 481 2-Mercapto-2,3-dihydro- -2-sulfid-Pyridinium-Salz E2, 767... 

The action of mineral acids on 2-(2 -oxocyclohexyl)methyl-6-chloronicotinic acid (140) yields 6-(4 -carboxy)butyl-2-hydroxy-5-oxo-6,7-dihydro-5/7-1 -pyrindine (141).98a 98e Chemical and spectra data, as well as an unequivocal synthesis starting with ethyl 2-bromomethyl-... 

Oxazol 4-tert.-Butyl-2-ethyl-4,5-dihydro- E21d. 3519 (2-NH2-ol + R-COOH)... 

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