Chemoselective reactions of 3,6-diacetylindoles towards araldehydes, hydrazine hydrate and bromine: Synthesis and antimicrobial activity of novel 6-pyridyl/6-hydrazinoacetyl/6-bromoacetyl-3-acetylindole derivatives

1137-114

Chemoselectivity of bisindole tetracarboxylate towards hydrazine hydrate:Synthesis and antimicrobial activity of diethyl 5,5'-bis(2,5-dimethylpyrrol-1-ylaminocarbonylmethoxy)-2,2' -dimethyl-1, l' -(ethane-1,2-diyl)di(1<i>H</i>-indole )-3,3'-dicarboxylate

31-35Diethyl 5,5' -dihydroxy-2,2'-dimethyl-1,1' -(ethane-1,2-diyl)di(1H-indole)-3,3'-dicarboxylate 3 has been prepared in one-flask procedure by the condensation of diethyl 3,3'-(ethane-2,2' -diyldiimino )butenoate 1 with 1,4-benzoquinone 2 in 1:2 molar ratio. Reaction of 3 separately with methyliodide and ethyl chloroacetate affords the corresponding O-alkylated derivatives 4 and 5, respectively. Exclusive formation of diethyl 5,5'-bi-(hydrazinocarbonylmethoxy)-2,2' -dimethyl-1,1'(ethane-1,2-diyl)di(1H-indole)-3,3'-dicarboxylate 6 from 5 reveals the chemoselectivity of 5,5'-ester function towards nucleophilic attack of hydrazine hydrate. This dicarbohydrazide 6 on reacting with acetonylacetone furnishes diethyl 5,5-'bis(2,5-dimethylpyrrol-l-ylamino-carbonylmethoxy)-2,2' -dimethyl-1,1'-(ethane-1,2-diyl)di(1H-indo le)-3,3'-dicarboxylate 8.Conformations of all these bisindole derivatives have been established. Compounds 3, 4, 5, 6 and 8 have also been screened for their antibacterial and antifungal activities

Some electrophilic substitution reactions on 1-substituted-3-acetyl/carbethoxy-5-hydroxy-2-methylindole and the antimicrobial activity of these new indole derivatives

1679-1685Aminomethylation under Mannich reaction conditions on 3-carbethoxy-1-furfuryl-5-hydroxy-2-methylindole 1 and the corresponding bromo derivative 3 occurs regioselectively at C4 position to furnish the 4-isogramines 2a-d/4a-d. Nitration of 3-carbethoxy/acetyl-1-furfuryl-5-hydroxy-2-methylindoles 1/8 with hydrated ferric nitrate produces 3-carbethoxy/acetyl- 4, 6-dinitro-1-furfuryl-5-hydroxy-2-methylindoles 6/9. Nitration of 4-isograamine 2 and bromoindole 3 involves ipso-substitution and furnish the 4, 6-dinitroindole derivative 6 and not the expected 6-nitro-4-isogramine 5/6-bromo-4-nitroindole 7. However, nitration of 3.6-diacetylindoles 18a-d and triacetylindole 10 yields 4-nitroindole derivatives 19a-d/11 wherein the acetyl group remain intact without involving in any ipso-substitution. Acetylation under Friedel-Crafts reaction conditions on 3-acetyl-1-furfuryl-5-hydroxy -2-methylindole 8 occurs at both C6-position of indole and C5-position of furan to furnish the triacetylindole 10. Bromination of 1 with bromine in acetic acid or bromine in dioxane produces only 6-bromoindole 3. The structures of all these newly synthesised compounds are confirmed by their spectral and analytical data and all these compounds are screened for antimicrobial activity

Chemoselective reaction of bisheterocycle dicarboxylate towards hydrazine hydrate: Synthesis and antimicrobial activity of some new trisheterocycles:5-Pyrrolylaminocarbonyl/ oxadiazolyl/mercaptooxadiazolylmethoxy-1-furfuryl-2-methylindoles

3108-3112Chemoselectivity of C5-ester over C3-carbethoxy ester function of the bisheterocycle dicarboxylate towards the nucleophilic attack of hydrazine hydrate has been evidenced by the exclusive formation of 1-furfuryl-3-carbethoxy-5-hydroxy-2-methylindol-5-yloxyacetic acid hydrazide which is reacted separately with acetonyl acetone, triethyl orthoformate, carbon disulphide and boiling ethanolic potassium hydroxide to furnish respectively the 1-furfuryl-3-carbethoxy-5-(2, 5-dimethylpyrrol-1-yl)aminocarbonylmethoxy-2-methylindole, 1-furfury l-3-carbethoxy-5-(1, 3, 4-oxadiazol-2-yl)methoxy-2-methylindole and 1-furfuryl-3 carbethoxy-5-(5-mercapto-1, 3, 4-oxadiazol-2-yl)methoxy-2-methylindole. The newly synthesized compounds are screened for their antibacterial and antifungal activities

Chemoselective reaction of benz[<i>g</i>]indole dicarboxylate towards hydrazine hydrate: Bisheterocycles: Synthesis and antimicrobial activity of some new 1-[2-hydroxyethyl]-3-ethoxycarbonyl-5-oxadiazolyl/triazolyl/ pyrrolylaminocarbonylmethoxy-2-methylbenz[<i>g</i>]indoles

794-800The exclusive formation of 1-[2-hydroxyethyl]-3-ethoxycarbonyl-2-methyl benz[g] indol-5-yloxyacetic acid hydrazide 6 from 1-[2-hydroxyethyl]-3-ethoxycarbonyl-5-methoxycarbonylmethoxy-2-methylbenz[g]indole 3 revealed the chemo­selectivity of the C5-ester over C3-ester towards nucleophilic attack of hydrazine hydrate. This monocarbohydrazide 6 is reacted separately with CS2/KOH, acetonyl acetone and isothiocyanates to secure the desired 1-[2-hydroxyethyl]-3-ethoxycarbonyl-5-(5-mercapto-1,3,4,-oxadiazl-2-y1)methoxy-2-methylbenz[g]indole 7, 1-[2-hydroxyethyl]-3-ethoxy-carbonyl-5-(2,5-dimethylpyrrol-1-yl)aminocarbonylmethoxy-2-methylbenz[g]indole 8 and 1-[2-hydroxyethyl]-3-ethoxy­carbonyl-5-(N-substituted thiosemicarbazinocarbonyl)methoxy-2-methylbenz[g]indole 9a-c. These thiosemicarbazides 9a-c are reacted with 4% NaOH to produce the 1-[2-hydroxyethyl]2-methybenz[g]indol-5-(4-substituted-5-mercapto-1,2,4-triazol-3-yl)methoxy-3-caboxylic acids 10a-c. All theses newly synthsised compounds are screened for their antimicrobial activities

Synthesis and antimicrobial activity of some new 1-cyclohexyl-3-carbethoxy-2-methyl-5- oxadiazolyl/triazolyl and pyrrolylaminocarbonylmethoxyindoles

2896-2900The exclusive formation of 1-cyclohexyl-3-carbethoxy-2-methylindol-5-yloxyacctic acid hydrazide 3 when 1-cyclohexyl-3-carbethoxy-5-methoxycarbonylmethoxy-2-methylindole 2 is reacted with hydrazine hydrate, reveals the chemoselectivity of C5-ester over C3-carbethoxy ester function towards the nucleophilic attack of hydrazine hydrate. This monocarbohydrazide was treated separately with triethylorthoformate, acetonylacetone in boiling absolute ethanol, CS2/KOH and further on acidification with HCl, CS2/KOH followed by treatment with hydrazine hydrate, KCNS/HCl and treatment with 10% NaOH, to furnish 1-cyclohexyl-3-carbethoxy -2-methyl-5-(1,3,4-oxadiazol-2-yl) methoxyindole 4, 1-cyclohexyl-3-carbethoxy-2-methyl-5-(2,5-dimethylpyrrol-1-yl) aminocarbonylmethoxyi ndole 5, 1-cyclohexyl-3-carbethoxy-2-methyl-5-(5-mercapto-1 ,3,4-oxadiazol-2-yl) methoxyindole 6 and 1-cyclohexyl-3-carbethoxy-2-methyl -5-(4-amino-5-mercaptotriazol-3-yl)methoxyindole 7 and 1-cyclohexyl-3-carbethoxy-2-methyl-5-(4H-5-mercapto-1,2,4-triazol-3-yl)methoxyindole 8, respectively. The newly synthesized compounds have been evaluated for their antimicrobial activity and their structures have been confirmed on the basis of analytical and spectral data

Chemoselective reaction of indole 1,3-dicarboxylates towards hydrazine hydrate: Bisheterocycles: Synthesis and antimicrobial activity of some new 2-methyl-3-ethoxycarbonyl-1-oxadiazolyl/thiazolidinonyl/pyrrolyl­aminocarbonylmethylindoles

1663-1668Chemoselectivity of 1-ester over C3-ester of the indole dicarboxylates 3a,b towards the nucleophilic attack of hydrazine hydrate has been evidenced by the exclusive formation of 1-hydrazinocarbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles 5a,b which have been further reacted separately with CS2/KOH, p-chlorobenzaldehyde and acetonyl acetone to furnish the 1-(5-mercapto-1,3,4-oxadiazol-2-yl)methyl-3-ethoxycarbonyl-5-substituted-2-methylindoles 6a,b, 1-p-Chlorobenzyl­idene­hydrazinocarbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles 7a,b and 1-(2,5-dimethyl­pyrrol-1-yl)­amino­carbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles 8a,b respectively. The Schiff’s bases 7a,b are reacted separately with thioglycolic acid to get the desired 1-(2-p-chlorophenyl-4-thiazolidinon-1-yl)aminocarbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles 9a,b. These newly synthesised compounds are screened for their antibacterial and antifungal activities

<span style="font-size:20.5pt;mso-bidi-font-size:14.5pt; font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Synthesis and antimicrobial activity of novel 4<i style="mso-bidi-font-style:normal">H</i>-pyrano[2,3-<i style="mso-bidi-font-style:normal">f</i>]indole derivatives^†</span>

178-1825-Hydroxyindoles 1a-b have been subjected to regioselective Friedel-Craft 's acetylation to secure 3,6-diacetyl-5- hydroxyindoles 2a-b which on condensation with benzoic acids by using pyridine and phosphorous oxychloride furnish the required esters 3a-f in good yields. These esters 3a-f are subjected to Baker-Venkataraman transfomlations to obtain 3- acetyl-6-benzoylacetyl-5-hydroxyindoles 4a-f which are refluxed in AcOH and conc. HCI to afford the novel 2-phenyl-4H-pyrano[ 2,3-f]indol-4-one derivatives 5a-f. Similarly when 4a-f are heated with Ac2O and A<i style="mso-bidi-font-style: normal">cONa new 2-methyl-3-benzoyl-4H-pyrano[2,3-f]indol-4-one derivatives 6a-f are obtained. All these new compounds have been screened for their antibacterial and antifungal activities.</span

1,3-Dipolar cycloaddition reactions: Synthesis and antimicrobial activity of novel 1-triazolylethylindole and 1-triazolylethylbenz[g]indole derivatives

1068-1073Indole azide 4 and benz[g]indole azide 12 are reacted separately with dimethyl acetylenedicarboxylate to secure the desired 1-[4,5-dimethoxycarbonyl-1,2,3-triazol-1-yl]ethyl-3-ethoxycarbonyl-5-methoxy-2-methylindole 5 and 1-[4,5-di­methoxy­carbonyl-1,2,3-triazol-1-yl]ethyl-3-ethoxycarbonyl-5-methoxy-2-methylbenz[g]indole 13, respectively. The reac­tion of indole azide 4 and benz[g]indole azide 12 with ethyl propiolate has been found to be regiospecific and produce only the 1-[4-ethoxycarbonyl-1,2,3-triazol-1-yl]ethyl-3-ethoxycarbonyl-5-methoxy-2-methylindole 6 and 1-[4-ethoxycarbonyl-1,2,3-triazol-1-yl]ethyl-3-ethoxycarbonyl-5-methoxy-2-methylbenz[g]indole 14, respectively. Indole azide 4 is also reacted with ethyl phenylpropolate to secure two isomeric products 1-[4-ethoxycarbonyl-5-phenyl-1,2,3-triazol-1-yl]ethyl-3-ethoxycarbonyl-5-methoxy-2-methylindole 8 and 1-[4-phenyl-5-ethoxycarbonyl-1,2,3-triazol-1-yl]ethyl-3-ethoxycarbonyl-5-methoxy-2-methylindole 9. All these newly synthesised compounds are screened for their antimicrobial activities

Synthesis and antimicrobial activity of novel 5-tetrazolyl/oxadiazolyl/benzimidazolylmethoxyindole derivatives

188-1911-Alkyl-3-acetyl-2-methylindol-5-yloxyacetonitriles 2a,b, prepared by reacting 5-hydroxyindoles 1a,b with chloroacetonitrile have been converted to 1,2,3,4-tetrazolylindoles <b style="mso-bidi-font-weight: normal">3a,b using NaN3. <span style="font-size:14.0pt; mso-bidi-font-size:8.0pt">LiCI and NH<span style="mso-bidi-font-size: 6.0pt">4C1 in dry dimethylformamide. Conversion of tetrazolylindoles 3a,b into 1,3,4-oxadiazolylindoles 4a,b has been achieved by heating with acetic anhydride. Hydrolysis of 1-alkyl-3-ethoxycarbonyl-5-ethoxycarbonylmethoxy-2-methylindoles 5a,b with ethanolic NaOH gives the corresponding diacids 6a,b, which on heating with o-phenylenediamine in 6N HCI undergo condensation with concomitant decarboxylation to yield the 1-alkyl-5-(benzimidazol-2-ylmethoxy)-2- methylindoles 7a,b. The newly synthesised bisheterocycles have been screened for their antibacterial and antifungal activities.</span