Carbazole, 9-methyl-3-

In 1988, Furukawa et al. reported the isolation of 3-formylcarbazole (3) from the root bark of M. euchrestifolia (22). Three years later, McChesney and El-Feraly isolated 3-formylcarbazole (3), along with methyl carbazole-3-carboxylate (4), from the roots of Clausena lansium (23). The roots of this ornamental tree are used in traditional medicine in Taiwan to treat bronchitis and malaria (23). In 1992, Bhattacharyya et al. described the isolation and structural elucidation of 3-formylcarbazole (3) from G. pentaphylla (24). 

In 2003, Sunthitikawinsakul et al. described the anti-mycobacterial activity of various 3-methylcarbazole derivatives, including 3-formylcarbazole (3), methyl carbazole-3-carboxylate (4) (see Scheme 2.2), clausine K (clauszoline-J) (51) (see Scheme 2.11), and 7-methoxymukonal (68) (see Scheme 2.14) against Mycobacterium tuberculosis H37Ra. Except for clausine K (clauszoline-J) (51), all of these alkaloids also showed anti-fungal activity against Candida albicans (442). In 2005, Eranzblau et al. reported the in vitro anti-TB activity of various carbazole derivatives such as 3-formylcarbazole (3), methyl carbazole-3-carboxylate (4) (see Scheme 2.2), lansine... 

A new benzannulation methodology was developed in order to overcome the limitations of electrocyclic ring closure of divinylindoles. The cyclization is achieved via an allene-mediated electrocyclic reaction of 2,3-difunctionalized indoles. This method is more efficient for the synthesis of highly substituted 2-methyl carbazole alkaloids (559). The 3-alkenyl-2-propargylindole 557, a precursor for the allene intermediate, was prepared from 2-formylindole over several steps using simple functional group transformations (536,537) (Scheme 5.20). 

Other chemical reagents that have been used to dehydrogenate are diphenyl disulfide for 1,2,3,4-tetrahydrocarbazole itself, N-bromosuccinimide in pyridine for 1-ethoxycarbonyl-1,2,3,4-tetrahydrocarbazole, selenium dioxide for 9-methyl-1,2,3,4-tetrahydrocarbazole (a 1 5 mixture of 9-methyl-carbazole and 1-oxo-1,2,3,4-tetrahydrocarbazole was obtained ), and manganese dioxide to aromatize 1-methyl- and l,4-dimethyl-6-alkoxy-3-formyl-1,2,3,4-tetrahydrocarbazoles and 1,9-diprenyl-1,4-dihydrocarba-zole. ... 

Methylindole condenses with methyl vinyl ketone in acetic acid-acetic anhydride in the presence of hydroquinone to produce 10% 2-methyl-carbazole and with 2-hydroxymethylene cyclohexanones to produce tetracycles 375 (R = = H R = Me, R = H R = H, R = Me) in... 

In addition to products E and F, 16% (at 60% conversion) of 9-methyl-carbazole G has been isolated. Carbazole formation implies a loss of S02 from sulfone H and subsequent ring closure (Equation 30). 

A recently reported regioselective photoreduction of benzoates by photosensitized electron transfer reaction was applied to nucleosides [85]. In presence of jV-methyl-carbazole as the electron donor sensitizer and in an isopropanol, water solution, w-trifluoromethylbenzoates of adenosine 83 or benzoates of uridine 84 give deoxygenated products in good yields (73 %). 

Salmon, J.-M., Kohen, E., Kohen, C. and Viallet, P. Microspectrofluorometric study of free/bound NAD(P)H ratio in carbazole and methyl carbazole treated cells. In ... 

Figure 1. Test for carbazoles in the products as a function of time with unimpregnated carrier at 200flC. Product concentration relative to the feed. a Carbazole x Methyl carbazoles Dimethyl carbazoles Trimethyl carbazoles...

Figure 2. Relative distribution of methyl carbazoles in the product,...

C-curarine came from zinc dust distillation of norcurarine, which yields 3-methylindole, 3 ethylindole, 3-ethylpyridine, carbazole, and methyl-carbazole (128). 

Carbazole-l,4-quinones, the key intermediates of this approach, can be even more effidently prepared by the palladium(II)-catalyzed oxidative cydization (see below. Scheme 15.17). In a screening for anti-TB active carbazoles, 3-methoxy-2-methyl-carbazole-l,4-quinone showed significant inhibition of Mycobacterium tuberculosis strain H37RV, with an MIC90 value 2.2 p.g/mL (9 p,M) [40]. Thus, carbazoles may be developed as anti-TB drug candidates by structural modifications. 

The reactivity orders are found as indole > methylated aniline > methylated indole > quinoline > benzoquinoline > methylated benzoquinoline > carbazole > methylated carbazoles. 

UV-absorption studies on aromatic polymers at low temperature solid glasses seem to be scarce. In Figure 1, the low temperature spectra of PVCA and its monomeric model N-Methyl-carbazole in MTHF glass at 77 K are compared (17). The monomer clearly shows better resolution due to sharper absorption bands in the two lowest transitions but again the hypochromic effect in the polymer is evident. 

Photochemical formylation of carbazole,methyl-carbazoles,and diphenylamine has been observed when they are illuminated with ultra-violet light or sunlight in chloroform solution, while chlorination products of pyrene and perylene have been observed when these arenas are irradiated in carbon tetrachloride.A report of the light induced chlorination of pyridine by chlorine in the gas phase has also appeared. 

Heptaphylline (1) has been synthesised by sequential C(3)-formylation and C(l)-isopentenylation of 2-hydroxycarbazole. l-Formyl-2-hydroxy-3-methyl-carbazole reacts with the Wittig reagent from 2-methylprop-l-en-3-yltriphenyl-phosphonium chloride-sodium hydroxide to generate girinimbine (2a) 2-hydroxy-3-methylcarbazole reacts with citral to give ( )-mahanimbine (3a). 

Auf diese Weise erhalt man u.a. 3-Formyl-9-methyl-carbazol (6 Stdn.)438... 

Ethyl-3-formyl-carbazol (10 Stdn.)448 9-Alkyl-6-brom-3-formyl-carbazole (6 Stdn.)438 9-Alkyl-3-formyl-6-nitro-carbazole (6 Stdn.)438 3-Formyl-6-methoxy-l-methyl-carbazol (4 Stdn.)445... 

Methyl-carbazol bildet mit Lithium/Propylamin jedoch 9-Methyl-J, 2,3,4,4a,9a-hexahydro-carbazol2 (71% d.Th., Kp 125-135°), wahrend mit Natrium/Ammo-niak/Ammoniumchlorid 9-Mcthyl-l,4-dihydro-carbazol21 (F 93-95°) und mit Na-trium/Ammoniak/Athanol 9-Methyl-l,4,5,8-tetrahydro-carbazol3 (F 142-144°) entste-hen ... 

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