Indole derivatives acetophenone

The asymmetric reaction of cyclic ketones can be performed with chiral bi-naphthylphosphines (Eq. 8) [47-50]. The reaction of acetophenones with ortho-bromonitrobenzenes followed by reduction affords indole derivatives (Eq. 9)... 

Reaction of the carbanion 222 results in the formation of the acetophenone ylid 223, which on treatment with acids or nitrosobenzene is converted to the indole derivatives 224 or 225. Ring closure of 223 with orthoesters yields the quinolones 226 - with carbon disulfide 227 is obtained (Scheme 38). Treatment of lA with dimsyl sodium (228) leads to 229, from which with aldehydes the quinolinones 231 are obtained. Reaction with HNO2 leads to the cinnoline 232, and with carboxy-... 

Figure 2. Formulas of selected D-A compounds which contain 4-dialkylamino group as an electron donor and reveal dual fluorescence behaviour. Top /)-cyano-A,A-dimethylaniline (I, CDMA) and its model derivatives p-cyano-2,A,A-trimethylaniline (II), p-cyano-2,6,A.A-tetramethylaniline (III, CTMA)./)-aminobenzonitrile (IV, ABN) and l-ethyl-2,3-dihydro-indole-5-carbonitrile (V. BIN). Middle 4-(dimethylamino)pyrimidine (VI), 4-(diethylamino)pyrimidine (VTI), 4-(dimethylamino)-5-methylpyrimidine (VIII), 4-(diethylamino)-5-methylpyrimidine (IX) and 4-(dimethylamino)-pyridine (X). Bottom methyl 4-(dimethylamino)benzoate (XI, DMAMB), ethyl 4-(dimethylamino)benzoate (XII, DMAEB), p-(dimethylamino)-benzaldehyde (XIll) and />-(dimethylamino)acetophenone (XIV).

There are alternative methods to produce indoles. Acetophenone reacts with 2-chloro nitrobenzene derivatives in the presence of a phenol and a palladium catalyst to give an indole. ... 

BenzolMfurans yielded (2 + 2)-cycloadducts (191) with dimethyl-maleic anhydride, via excitation of an initially formed charge-transfer complex, together with oxetans.218 Similar (2 + 2)-cycloadducts (192) were obtained from quinones and benzoU>] furan and some of its derivatives.143,200 Irradiation of W-acyl-l//-indoles in the presence of olefins, either with or without acetophenone as a sensitizer, produced a series of (2 + 2)-cycloadducts 193, usually as a mixture of exo- and endoisomers.219 The olefins that give a (2 + 2)-cycloadduct are either electron-rich olefms, such as ethyl vinyl ether and vinyl acetate, or... 

In the 1980s, a series of papers re-awakened interest in the synthesis of 5,6-dihydroxyindoles. In the first of these papers (82JMC263) indole 1 and its 4- and 7-methyl derivatives 16 and 17 were synthesized and evaluated for their ability to inactivate eatechol-O-methyl transferase. The synthetic scheme employed for the methylated derivatives was based on the dinitrostyrene approach starting from an appropriate aeetophenone derivative (Scheme 7). The acetophenones were converted... 

For 3-MI (IV), structure V Is proposed as the major product of photooxldatlon In water. This structure, o-(N-formyl)amlno-acetophenone (molecular weight > 163), Is supported by the mass spectrum of the 3-MI product found In aqueous CRM-1 (120 [lOOZ], 92 [51%], 135 [45%], and 163 [16Z]), Spectra of the other product peaks suggest that they are analogous products (acylamlno derivatives) from the photooxldatlon of other alkylated Indoles,... 

Samarium diiodide-induced intermolecular coupling of aldehydes and ketones to indoles with an electron-withdrawing group at the 3-position of the indole have also been reported [19]. Carbonyl compounds including acetone, acetophenone, benzophenone, pivaldehyde, and isobutyraldehyde added to the C-2 position of the indole to give the thermodynamically stable trani-dihydroindole derivatives 27. 

Cycloaddition reactions of the indole 2,3-double bond are not limited to alkenes as partners. Acetylenic compounds have also been used in photochemical cycloaddition reactions with indoles to produce cyclobutenone derivatives. There have been extensive studies on the reaction of indoles with dimethyl acetylenedi-carboxylate (61, DMAD), which produce a number of structurally distinct products [31]. By devising a photosensitized cycloaddition reaction of DMAD to activated indoles 60 in the presence of acetophenone, Neckers and Davis were able to produce the cyclobutene derivatives 62 in good yields (Scheme 14) [32]. The resulting cyclobutenes can then be converted to the corresponding benzazepines 63 via thermal ring-opening reactions. 

An important use of H CHO has been found in amino[ " C]methylations of nucleophiles in the presence of primary and secondary amines (Mannich reaction). Nucleophilic substrates include C—H acidic aliphatic compounds (e.g. aldehydes, ketones, esters, nitroalkanes and nitriles), and reactive aromatic and heteroaromatic substrates such as indoles, furans and phenols. The amino[ C]methylations of some C—H acidic methyl, methylene and methine substrates are exemplified in Figure 5.44. The immediate products, alkyl- or dialkylamino[ C]methylene derivatives ( Mannich bases ), can undergo a number of useful synthetic transformations. Condensation of H CHO with acetophenone and dimethylamine provided the carbon- 14-labeled /3-aminoketone 147 in 51 % yield. /3-Aminocarbonyl compounds such as 147. whQe stable at room temperature, can eliminate... 

Aryl-lH-indol-3-carbaldehyde derivatives underwent Claisen-Schmidt condensation with different acetophenones in ethylene glycol and few drops of piperidine under microwave irradiation. The reaction proceeded within 3-10 min at 750 W to afford substituted 3-(2-aryl-lH-indol-3-yl)-prop-2-en-l-one derivatives, which react with phenylhydrazine in absolute ethanol and few drops of glacial acetic acid under microwave irradiation at 350 W in 1-2 min with successive periods of 30 sec to afford the corresponding indolylpyrazoline analogs (Zahran et al., 2010). On the other hand, the conventional method requires 9-12 h. 

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