Cryptolepine analogues containing basic aminoalkyl side-chains at C-11: Synthesis, antiplasmodial activity, and cytotoxicity

Iodine-mediated one-pot synthesis of indoles and 3-dimethylaminoindoles via annulation of enaminones

“…Accordingly, moderate to low yields were observed in the case of enaminones 3i-j and 3m-n, and no conversion at all was detected with enaminones 3h and 3k-l (Table 4, entries [8][9][10][11][12][13][14]. In contrast, the cyclization of enaminones 3o-p resulted in good yields of the corresponding indoles 1o-p (Table 4, entries [15][16].…”

“…At first, αanilinocarbonyl compounds 4a-n were prepared in good to excellent yields (60-99%) under conditions similar to those previously reported (Table 1, entries [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. 21 The mixture of anilines 5a-g, potassium carbonate and potassium iodide were treated with the corresponding methyl bromoacetate (6a) or chloroacetone (6b), in dry acetone as the solvent, at 60 ºC for 12 h. However, for analogues 4o-p, which derive from the 2-bromoacetophenones 6c-d, this method was only able to provide the desired products in low to moderate yields (30-64%).…”

“…However, even for the non-activated substrates 4k-l, the respective indoles 2k-l were obtained, albeit in low yields (Table 6, entries [11][12]. Likewise, α-anilinoacetophenones 4o-p satisfactorily reacted to give indoles 2n-o, respectively (Table 6, entries [14][15].…”

“…12 In the case of 3-aminoindoles and cyclic-fused analogues, they have been found to be effective as anticancer, 13 antiplasmodial and cytotoxic agents. 14 As a consequence of these relevant activities and applications, a great number of synthetic routes leading to 2-substituted indoles have been described in the literature. [1][2][3] However, the protocols reported for the synthesis of 3-aminoindole derivatives are limited in scope, and usually require multistep preparation of the starting materials.…”

A novel one-pot three-step synthesis of 2-(1-Benzofuran-2-yl)quinoline-3-carboxylic acid derivatives

“…[28][29][30][31][32][33] Recently, there is much current interest in assembling quinoline ring with heterocyclic systems, which represent privileged moieties in medicinal chemistry, and are ubiquitous sub-structures associated with biologically active natural products. [34][35][36][37][38] For example, 2-(furan-2-yl) quinoline-4-carboxylic acid as well as analogues ( Figure 1) was reported to have the inhibition of C. albicans prolyltRNA synthetase and showed potent in vitro antifungal activities against dermatophytes. 39,40 In light of the above reports and because of the potent biological activities of quinoline ring system and 2-substituted benzo[b]furan derivatives, we felt that there is a real need for the synthesis of new prototypes by combining both quinoline ring system and benzo [b] furan moiety in the same molecule at 2-position, which might be important for pharmacological studies or creating new medicinal properties.…”