ChemInform Abstract: A Practical Method for N‐Methylation of Indoles Using Dimethyl Carbonate.

Jiang, Xinglong; Tiwari, Ashish; Thompson, Maethonia; Chen, Zhihong; Cleary, Thomas P.; Lee, Thomas B. K.

doi:10.1002/chin.200218116

Cited by 9 publications

(18 citation statements)

References 1 publication

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“…As a new green chemical material, dimethyl carbonate [6] can react as a carbonylating agent, esterifying agent, methylating agent, and so on [7][8][9][10][11][12][13][14][15], since its molecular structure contains carbonyl, carboxyl and methyl groups. However, the alkylation of the tertiary amine with the dimethyl carbonate to produce quaternary ammonium salts has rarely been reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Lauryl Trimethyl Ammonium Surfactants with New Counteranion Types

Shui

et al. 2009

J Surfact & Detergents

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A new family of lauryl trimethyl ammonium surfactants of the general formula CH 3 (CH 2 ) 11 N ? (CH 3 ) 3 X -(X = CH 3 OCOO, HCOO, CH 3 COO, CH 3 CHOHCOO) were prepared and characterized both structurally and as aqueous surfactants. Lauryl trimethyl ammonium monomethyl carbonate was synthesized by using dimethyl carbonate (DMC) as the alkylating agent and lauryl dimethyl amine as the starting material. The latter compound was reacted with formic acid, acetic acid, and lactic acid, respectively, to give the corresponding quaternary ammonium salts with other counteranions. They were structurally characterized by IR, 1 H NMR, MS. Members of this family reduced the surface tension of water to 32-38 mN/m at concentration levels of 10 -2 mol/L.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Lauryl Trimethyl Ammonium Surfactants with New Counteranion Types

Shui

et al. 2009

J Surfact & Detergents

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“…5‐(3′‐Indolyl)‐3‐substituted‐1,2,4‐triazoles 6a‐g and 7a‐o were prepared as described in the Scheme 1. The indole‐3‐carboxaldehyde 2 and N ‐methylindole‐3‐carboxaldehyde 3 were prepared according to the literature procedures (32,33). Indole‐3‐carbonitriles ( 4 and 5 ) were synthesized in good yields from the corresponding indole‐3‐carboxaldehydes ( 2 and 3 ) by reacting with hydroxylamine hydrochloride in the presence of sodium formate and formic acid at reflux temperature.…”

Section: Resultsmentioning

confidence: 99%

“…Indole‐3‐carboxaldehyde ( 2 ) was synthesized from commercially available indole as described in the literature (32,33). The N‐methylation of 2 was carried out using dimethylcarbonate in the presence of potassium carbonate (32,33).…”

Section: Methodsmentioning

confidence: 99%

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Synthesis of Novel Indolyl-1,2,4-triazoles as Potent and Selective Anticancer Agents

Kumar

Narayanam

Chang

et al. 2011

Chemical Biology &Amp; Drug Design

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A diverse series of 22 indolyl-1,2,4-triazole congeners (6 and 7) have been synthesized from the reaction of indole-3-carbonitrile (4) or (5) with appropriate acid hydrazides in the presence of potassium carbonate. Synthesized compounds were evaluated for their cytotoxicity against six human cancer cell lines, and some of the compounds displayed promising activity. In particular, 3-(3',4',5'-trimethoxyphenyl)-5-(N-methyl-3'-indolyl)-1,2,4-triazole (7i) and 3-(4'-piperidinyl)-5-(N-methyl-3'-indolyl)-1,2,4-triazole (7n) were the most promising and broadly active compounds against the tested cell lines. It was interesting to note that the trimethoxyphenyl analog 7i showed twofold selective cytotoxicity against PaCa2 cell line (IC(50) 0.8 μm), whereas piperidinyl analog 7n was found to be selectively cytotoxic against MCF7 cell line (IC(50) 1.6 μm). Notably, the 4-fluorophenyl derivative 7c exhibited selective cytotoxicity against PC3 cell line (IC(50) 4 μm). The structure-activity relationship study revealed that substituents including 3,4,5-trimethoxyphenyl, 3,4-dimethoxyphenyl, 4-benzyloxy-3-methoxyphenyl, 4-piperidinyl, 4-fluorophenyl and N-methylindole are beneficial for the activity of indolyl-1,2,4-triazoles (6 and 7).

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“…Isocyanates could be formed from N-aryl O-alkyl carbamates (Scheme 1) [14][15][16][17][18][19][20][21][22][23][24]. The problem arises from the dual behaviour of organic carbonates as carbamoylating and alkylating reagents (Scheme 2) [25][26][27][28][29][30][31][32][33][34]. While the desired carbamoylation leading to carbamates occurs in aliphatic amines, aromatic amines tend to undergo predominantly N-alkylation, the formation of carbamates being a very minor process [35].…”

Section: Introductionmentioning

confidence: 99%

Towards a Phosgene-Free Synthesis of Aryl Isocyanates: Alcoholysis of N-phenylurea to N-phenyl-O-methyl Carbamate Promoted by Basic Metal Oxide Nanoparticles and Organocatalysts

2009

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There is an urgent need to develop new processes for the synthesis of polyurethanes and polycarbonates different from the current technology based on the use of phosgene. In the case of polyurethanes, the reaction of phosgene with aromatic amines renders N-aryl isocyanates that are the co-monomers for these polymers. In the search for a phosgene-free process for the synthesis of N-aryl isocyanates, N-aryl carbamates could play a key role of synthetic precursors. N-Aryl carbamates can be prepared in turn by alcoholysis of N-aryl ureas. Herein, we compare the catalytic activity of three homogeneous catalysts and four heterogeneous metal oxides for the methanolysis of N-phenylurea as a model probe for other aromatic ureas. In the present work we have carried out this reaction in the presence of KOH, 1,8-diaminonaphthalene (a protonic sponge), a dimeric phosphazene (strong, neutral soluble base) and nanometric ZnO, MgO, CaO and a mixed Mg/Al metal oxide derived from hydrotalcite calcination. Besides the target N-phenyl O-methyl carbamate, N-phenyl isocyanate and undesired aniline were also formed. It was observed that using KOH and diaminonaphthalene, aniline was formed preferentially with respect to the desired carbamate. In contrast, dimeric phosphazene forms the target N-phenyl O-methyl carbamate with 90% selectivity at 99% N-phenylurea conversion. In the case of the metal oxides, the best-performing solid catalyst was CaO that exhibits similar activity (99% N-phenylurea conversion) and carbamate selectivity (89%) as phosphazene. CaO performs as a truly heterogeneous catalyst and could be reused for a second run with only a 4 and 2% decrease in conversion and selectivity, respectively.

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ChemInform Abstract: A Practical Method for N‐Methylation of Indoles Using Dimethyl Carbonate.

Cited by 9 publications

References 1 publication

Synthesis and Characterization of Lauryl Trimethyl Ammonium Surfactants with New Counteranion Types

Synthesis and Characterization of Lauryl Trimethyl Ammonium Surfactants with New Counteranion Types

Synthesis of Novel Indolyl-1,2,4-triazoles as Potent and Selective Anticancer Agents

Towards a Phosgene-Free Synthesis of Aryl Isocyanates: Alcoholysis of N-phenylurea to N-phenyl-O-methyl Carbamate Promoted by Basic Metal Oxide Nanoparticles and Organocatalysts

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