Carbazole 9-acetyl

Carbon Hydrogen Nitrogen Sulphur Sodium Glucosamine -Elson-Morgan Idole HCl Uronic acid by CO2 by Carbazole Acetyl Cations Volatile... 

There are reports of an increasing number of palladium-assisted reactions, in some of which the palladium has a catalytic function. Thus furan and thiophene undergo facile palladium-assisted alkenylation giving 2-substituted products. Benzo[6 Jfuran and TV- acetyl-indole yield cyclization products, dibenzofurans and carbazoles respectively, in addition to alkenylated products (8UOC851). The arylation of pyrroles can be effected by treatment with palladium acetate and an arene (Scheme 86) (81CC254). 

H-Benzo[a]carbazole, 4,4a,5,l 1,1 la,l Ib-hexahydro-synthesis, 4, 283 Benzo[b]carbazole, N-acetyl-photochemical rearrangements, 4, 204 Benzo[/]chroman-4-one, 9-hydroxy-2,2-dimethyl-synthesis, 3, 851 Benzochromanones synthesis, 3, 850, 851, 855 Benzochromones synthesis, 3, 821 Benzocinnoline-N-imide ring expansion, 7, 255 Benzocinnolines synthesis, 2, 69, 75 UV, 2, 127 Benzocoumarins synthesis, 3, 810 Benzo[15]crown-5 potassium complex crystal stmcture, 7, 735 sodium complex crystal stmcture, 7, 735 Benzo[ 18]cr own-6 membrane transport and, 7, 756 Benzo[b]cyclohepta[d]furans synthesis, 4, 106 Benzocycloheptathi azoles synthesis, 5, 120... 

In synthesis of the alkaloid tjipanazole E (19b), the required symmetric dichloro-indolo[2,3-fl]carbazole 20a was obtained in a two-step procedure starting fi-om 4-chlorophenylhydrazine hydrochloride and 1,2-cyclohexanedione employing a Fischer indolization. Subsequent attachment of an acetyl-protected glucopyranosyl moiety to one of the nitrogens, followed by cleavage of the protective groups with ammonia in methanol, produced the desired natural product (91X7739). 

C20H25NO4 73074-37-2) see Atracurium besilate (/t)-tetrabydropapaverine 7V-acetyl-L-leucinate (C2gH4(,N207 141109-12-8) see Cisatracurium besylate ( )-tetrabydropapaverine bydrocbloride (C20H26CINO4 6429-04-5) see Cisatracurium besylate [ -( , 5 )]-2,3,4,9-tetrabydro-7V-(l-phenylethyt)-lff-carbazol-3-amine sulfate (1 1)... 

The total synthesis of the carbazomycins emphasizes the utility of the iron-mediated synthesis for the construction of highly substituted carbazole derivatives. The reaction of the complex salts 6a and 6b with the arylamine 20 leads to the iron complexes 21, which prior to oxidative cyclization have to be protected by chemoselective 0-acetylation to 22 (Scheme 13). Oxidation with very active manganese dioxide followed by ester cleavage provides carbazomycin B 23a [93] and carbazomycin C 23b [94]. The regioselectivity of the cyclization of complex 22b to a 6-methoxycarbazole is rationalized by previous results from deuterium labeling studies [87] and the regiodirecting effect of the 2-methoxy substituent of the intermediate tricarbonyliron-coordinated cyclo-hexadienylium ion [79c, 79d]. Starting from the appropriate arylamine, the same sequence of reactions has been applied to the total synthesis of carbazomycin E (carbazomycinal) [95]. 

Likewise, the N derivatives of carbazoles undergo PFR [116-118], Upon irradiation in cyclohexane A-acetyl-carbazole (157) gives the following products (quantum yields in parentheses) [119] 1-acetylcarbazole (158) (0.10), 3-acetyl-carbozole (159) (0.09), and carbazole (160) (0.06) (Scheme 43). The analogous A-acetyldiphenylamine gives the ortho- and para-acetylated products along with diphenylaniline with quantum yields of 0.20,0.096, and 0.048, respectively [119], Table 10 shows that these values decrease from cyclohexane to ethanol, but less markedly than in the case of acetanilide (see Table 8). 

Related substrates undergoing PFR include A-acetyl and A-(2-naphthoyl) esters of 5H- benzo [b] carbazole (Scheme 45) [121], Interestingly, the N-(2-naphthoyl) ester of carbazole 164 does not undergo PFR [121],... 

The acetate derivative of alkaloid uleine (104) obtained from its N-oxide 103 with acetyl chloride also undergoes cleavage by sodium borohydiide, giving carbazole 105 in high yield (85LA2073 Scheme 29). 

A new method for the benzannulation of indole involving the thermal cyclization of 3-buta-l,3-dienylindoles (560 and 561) was described for the synthesis of 3-methoxycarbazole alkaloids 562 (538-540). Contrary to earlier benzannulation procedures, this method involves the ring closure of a 3-buta-l,3-dienylindole without the loss of the methoxy group at the 3-position of the carbazole nucleus. The 3-buta-l,3-dienylindole required for this method was obtained by Sakamoto s procedure (538,539) starting from l-acetyl-2-methoxy-l,2-dihydroindole-3-one by... 

The reaction of the iron-complex salts 602 and 779 with the arylamine 973 afforded the iron complexes 976 and 977, both in 96% yield. Subsequent O-acetylation provided the corresponding acetates 978 and 979 in almost quantitative yield. The iron-mediated arylamine cyclization of the O-acetyl derivative 978 using very active manganese dioxide provided the carbazole 971 in 72% yield. Under similar reaction conditions, the O-acetyl derivative 979 gave a mixture of the carbazoles 972 and 980 in 35% and 17% yield, respectively (650,651) (Scheme 5.136). 

Carbazole, 9-methyl- and 9-acetylcarbazoles give 21 (R = H) and 3-acetyl-, 3-acetyl-9-methyl-, 3,6-diacetyl-, and 3,6-diacetyl-9-methylcarbazoles give 21 (R = Ac) on exposure to light from a xenon lamp in ethanolic sulfuric acid at 4°C in the presence of air. The transformations were explained by postulating initial photolytic cleavage to carbazole or 3-acetylcarbazole, respectively, followed by attack by singlet oxygen. ... 

In the acetylation of carbazole using dimethylacetamide-phosgene in methylene chloride, attack was shown to occur mainly at nitrogen (93 7, N C-3) trifluoroacetylation proceeded exclusively at nitrogen. Carbazole was more reactive in this sense than indole and much more reactive than pyrrole, a result paralleling their respective basicities at nitrogen (see Section II,A,3). N-Acylation under these conditions is thought to involve... 

The preparatively useful and simple N-alkylation procedure that utilizes a combination of carboxylic acid and sodium borohydride has been applied to carbazole giving an efficient 9-ethylation. Also of preparative importance is the use of thallous ethoxide as base in dimethylformamide-ether 9-methyl-, 9-ethyl-, n-propyl-, n-butyl-, benzyl-, and n-allylcarbazoles were efficiently produced, as well as 9,9 -dicarbazolylalkanes using C3, C4, and Cg dihalides. 2-Acetyl- and 2-vinylcarbazole were also efficiently 9-ethylated by this route. Another more recent approach to N-alkylation of carbazole utilizes potassium terf-butoxide in the presence of a catalytic quantity of 18-crown-6 9-methylcarbazole was prepared in high yield. ... 

The early use of aqueous potassium hydroxide in acetone for the acetylation and benzoylation of 3-nitrocarbazole using the acid chlorides has been subsequently repeated for the N-acetylation of 3,6-dinitrocarbazole with acetic anhydride, for the N-acetylation, ethoxycarbonylation, 4-fluorobenzoylation, and prop-2-ynoylation of 2-nitrocarbazole and for the methoxy- and ethoxycarbonylation of carbazole itself utilizing the chloroformate esters. 

Some use has the been made of the N-Grignard derivative of carbazole phenylacetyl (from the acid chloride), ethoxycarbonylcarbonyl, acetyl and 5-bromopent-4-enoyl, and various a-aminoacyl derivatives, (all... 

Several catalysts have been recommended for the N-acetylation of carbazole with acetic anhydride boron trifluoride, phosphorus pentoxide, concentrated sulfuric acid, zinc chloride, and phosphoric acid all gave 9-acetylcarbazole in moderate to good yield. 9-Acetylcarbazole can also be prepared using the Vilsmeier complex of N,N-dimethylacetamide and phosgene. ... 

The acetoxy group of 9-(l-acetoxyethyl)carbazole is easily displaced with alcohols. Easy displacement of a similarly situated halogen can be achieved, as has been noted before (see Section II,C,2) thus methanol converts 9-(l-chloro-2-iodoethyl)carbazole to 9-(2-iodo-l-methoxyethyI) car-bazole. Elimination of acetic acid or ethanol by strongly heating 9-(l-acetoxyalkyl)- or 9-(l-ethoxyalkyl)carbazoles gives 9-vinylcarbazoles. In the absence of acid, ( )-alkenes are produced, but acid catalysis leads to a mixture of E and Z isomers. Acetyl chloride in pyridine also effects ethanol elimination. ... 

Methanolysis of 9-(l-methoxyethyl)carbazole with methanol-hydrogen chloride gave carbazole and acetaldehyde dimethyl acetal. 9,9 -Di-(3,6-dibromocarbazolyl)methane gave 9-acetyl-3,6-dibromocarbazole with acetic anhydride and a trace of sulfuric add. ... 

In parallel with acylation (see Section II,D,3) nitration of 9-acetyl-carbazole, with silver nitrate-aluminium chloride, leads to the introduction of the electrophile at C-2, thus providing 2-nitrocarbazole efficiently after hydrolysis of the N-substituent. ° An early report that 9-tosylcarbazole is nitrated at C-1 could not be repeated. ... 

The alkaloid uleine 245 reacted with acetyl chloride-potassium carbonate, and its methiodide with aqueous base, to form ring-opened products, the carbazoles 246 (R = Ac and R = Me, respectively). 

An intramolecular cycloaddition brought about by reaction with acetyl chloride and di-isopropylamine converted the imine 377, presumably via 378, to a mixture of the carbazole 379 and the tetracycle 380 prolonged heating alone or brief treatment of the latter with p-toluenesulfonic acid caused elimination and the formation of 379. ... 

Condensation of the readily available N-pivaloyl ketone 259 (Scheme 77) with N-acetyl indolin-3-one (558) under acid conditions provides good yields of 1 l-azapyrido[3,4-6]carbazole 559, which represents an aza analogue of ellipticine (Scheme 168) (89JHC105). 

The acetylation of carbazole by acetic anhydride in the presence of boron trifluoride produces the 9-acetyl derivative. Further acetylation requires more vigorous conditions, using aluminum trichloride as a catalyst, and yields 2,9-diacetylcarbazole, which, upon base-catalyzed hydrolysis, produces 2-acetylcarbazole (80T3017). Acetylation of 1-phenyl-isoindole under mild conditions in the presence of pyridine yields l-acetyl-3-phenylisoin-dole, whereas the presence of an ester group at the 1-position deactivates the ring sufficiently to prevent acylation (81AHC(29)34l). 

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