- Quantum-chemical study of thermodynamics of hydrogen-bonded methylamine-methanol complexes reaction with dimethyl carbonate
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Thermodynamic parameters of the reactions of dimethyl carbonate cis-cis and cis-trans conformers with methylamine, methylamine dimer, and methylamine complexes involving linear methanol associates have been computed with the B3LYP and WB97XD quantum-chemi
- Samuilov,Balabanova,Samuilov,Konovalov
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Read Online
- CANNABINOID DERIVATIVES
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This disclosure relates to carmabinoid derivatives of Formula (1) wherein R4 or R7 is a carboxamide group, pharmaceutical compositions comprising these compounds and methods of using the carmabinoid derivatives. These compounds are potential carmabinoid receptor inhibitors, including CB1 and CB2 receptors. Formula (I)
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Paragraph 0159; 0173
(2021/04/10)
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- CANNABINOID DERIVATIVES
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This disclosure relates generally to cannabinoid derivatives having the structural formula (I), pharmaceutical compositions comprising them, and methods of using the cannabinoid derivatives. In some embodiments, R1 is - CH2CH=C(CH3)2, R2 is methyl, R3 is CsHn, R4 is -C(O)N(R4a)(R4b), R5 is H, R6 is OH, and R7 is H. Compounds of the present disclosure were tested in agonist and antagonist mode for both the CB1 and CB2 receptors. The tested compounds were generally found to exhibit activity in antagonist mode at the CB1 and CB2 receptor.
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Paragraph 0147-0148
(2021/06/04)
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- CANNABINOID DERIVATIVES
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This disclosure relates generally to cannabinoid derivatives, pharmaceutical compositions comprising them, and methods of using the cannabinoid derivatives.
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Paragraph 0136
(2021/06/22)
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- A preparation method of a dog or CAT
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The invention discloses a dog or CAT a kind of preparation method. Characterized in that (1) in order to inter-bromobenzene as the starting material, nitric acid/sulfuric acid system through the nitration reaction, process for preparing the intermediate 1 (2, 4 - dibromo nitrobenzene); (2) using the intermediate 1 as raw materials, through the ammonia in methanol solution of ammoniation reaction, to prepare the intermediate 2 (5 - bromo - 2 - nitroaniline); (3) using the intermediate 2 and thiophenol sodium solution as raw materials, through the condensation reaction, process for preparing the intermediate 3 (4 - phenylthio - 2 - nitroaniline); (4) intermediate 3 through the palladium catalytic hydrogenation reduction, to produce intermediate 4 (4 - phenylthio - 1, 2 - phenylenediamine); (5) intermediate 4 and melamine-based methyl formate solution, through the cyclization reaction, the profuse benzene reaches zuo generating products. The method clean environment, the production cost is low, with a purity of 99.5% or more, the yield is not lower than 84.0%.
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Paragraph 0011; 0028-0030
(2019/03/29)
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- Synthesis of dimethyl carbonate from methanol and urea over zinc-strontia mixed oxide catalysts
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A series of ZnO-SrO mixed oxide catalysts were prepared by co-precipitation with different compositions and tested for dimethyl carbonate synthesis from urea and methanol. The catalysts were characterized by BET surface area, XRD, NH3-TPD and CO2-TPD. The catalyst with 1:1 mol ratio exhibited high DMC yield of 35%. The uniform distributions of moderate to strong basic sites along with considerable number of acidic sites are accountable for high activity. Different reaction parameters were also screened and best possible conditions were established. The catalyst was easily recovered and reused with consistent activity.
- D., Dhana Lakshmi,B., Srinivasa Rao,Lingaiah
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- La-modified mesoporous Mg-Al mixed oxides: Effective and stable base catalysts for the synthesis of dimethyl carbonate from methyl carbamate and methanol
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A series of La-containing Mg-Al hydrotalcite-like (HTl) precursors with different La contents (Mg2+:Al3+:La3+ = 3:1:x, where x varies from 0 to 1.0) were synthesized using a co-precipitation method followed by hydrothermal treatment. X-ray diffraction and thermogravimetric measurements demonstrated that the yield of the HTl phase decreased with increasing La content. The La-modified Mg-Al mixed oxides (HTC-La) were then obtained by thermal decomposition of the corresponding HTl precursors, and the mesoporous structure was formed during calcination. It was demonstrated that the structure and surface basic properties of the HTC-La samples strongly depended on the amount of La additive. Simultaneously, the resulting HTC-La materials were used as solid base catalysts for the synthesis of dimethyl carbonate (DMC) from methyl carbamate (MC) and methanol. Then, the correlation between their basic properties and catalytic performance was studied in detail. The incorporation of a suitable amount of La into HTC-La catalysts was beneficial for the production of DMC, and a DMC yield of 54.3% with a high DMC selectivity of 80.9% could be achieved when x was tuned to 0.5 under the optimized reaction conditions. In addition, the HTC-La catalyst could be readily recycled while maintaining high catalytic activity and selectivity for DMC. Furthermore, in situ FTIR experiments were carried out to elucidate the adsorption behaviours of the reactants. On the basis of the experimental results, a plausible basic catalytic mechanism wherein MC and methanol were activated simultaneously on the basic sites of the catalyst was proposed for this catalytic reaction.
- Wang, Dengfeng,Zhang, Xuelan,Ma, Jie,Yu, Haiwen,Shen, Jingzhu,Wei, Wei
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p. 1530 - 1545
(2016/03/09)
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- Catalytic alcoholysis of urea to diethyl carbonate over calcined Mg-Zn-Al hydrotalcite
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The synthesis of diethyl carbonate (DEC) from urea and ethanol was carried out over Mg-Zn-Al composite oxide catalysts derived from hydrotalcites (HTs). The catalytic results showed that the ternary hydrotalcites calcined at 450 °C with Mg:Zn:Al = 1:1.7:1 exhibited superior catalytic activity, and the highest DEC yield was 67.8%. Similar to ethanol, other alcohols such as methanol and butanol can also be transformed to corresponding dialkyl carbonates. Catalysts were characterized by XRD, BET, SEM and TPD with the aim of establishing a relationship between performance and structure. The results indicated that MgZn1.7Al-450 with nanoplate morphology and more accessible active medium basic sites were favourable for obtaining much superior catalytic activity. Recycling experiments demonstrated that the catalyst could be successfully reused. This journal is
- Wang, Peixue,Liu, Shimin,Zhou, Feng,Yang, Benqun,Alshammari, Ahmad S.,Deng, Youquan
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p. 19534 - 19540
(2015/06/15)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF DIMETHYL CARBONATE USING IONIC LIQUIDS AS CATALYST
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The present invention relates to an improved process for the preparation of dimethyl carbonate and methyl-N-methyl carbamate starting from methanol and methyl carbamate catalyzed by ionic liquid catalyst in batch or continuous reactor.
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Paragraph 0035
(2015/06/25)
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- PROCESS FOR THE SYNTHESIS OF DIMETHYLCARBONATE
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The present invention discloses a process for the synthesis of dimethyl carbonate (DMC) and further methyl-N-methyl carbamate (MNMC) starting from urea or methyl carbamate using salts such as nitrate or triflate salts of rare earth elements, transition metals, alkaline earth and alkali metals as catalysts.
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Page/Page column 11
(2015/11/02)
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- SYNTHESIS OF DIMETHYL CARBONATE AND RELATED COMPOUNDS
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An improved process for synthesis of dimethyl carabonate (DMC) and related compounds further, starting from urea or methyl carbamate and methanol employing novel catalysts, double metal cyanides, cenospheres, hydrotalcites and hydrotalcite like compunds.
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Page/Page column 26-27
(2014/05/24)
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- Activation of electrophilicity of stable Y-delocalized carbamate cations in intramolecular aromatic substitution reaction: Evidence for formation of diprotonated carbamates leading to generation of isocyanates
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Although cations with three heteroatoms, such as monoprotonated guanidine and urea, are stabilized by Y-shaped conjugation and such Y-conjugated cations are sufficiently basic to be further protonated (or protosolvated) to dications in strongly acid media, only O-monoprotonated species have been detected in the case of carbamates even in magic acid. We found that the trifluoromethanesulfonic acid-catalyzed cyclization of arylethylcarbamates proceeds to afford dihydroisoquinolones in high yield. In strong acids, methyl carbamates are fully O-monoprotonated, and these monocations do not undergo cyclization even under heating. But, as the acidity of the reaction medium is further increased, the cyclization reaction of methyl phenethylcarbamates starts to proceed as a first-order reaction, with a linear relationship between rate and acidity. The sign and magnitude of the entropy of activation ΔS ? were found to be similar to those of other AAc1 reactions. These results strongly support the idea that further protonation of the O-protonated carbamates is involved in the cyclization, but the concentration of the dications is very low and suggests that the rate-determining step is dissociation of methanol from the diprotonated carbamate to generate protonated isocyanate, which reacts with the aromatic ring. Therefore, O-protonated carbamates are weak bases in sharp contrast to other Y-shaped monocations.
- Kurouchi, Hiroaki,Kawamoto, Kyoko,Sugimoto, Hiromichi,Nakamura, Satoshi,Otani, Yuko,Ohwada, Tomohiko
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p. 9313 - 9328,16
(2012/12/11)
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- Heterogeneous CeO2 catalyst for the one-pot synthesis of organic carbamates from amines, CO2 and alcohols
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Heterogeneous CeO2 catalyst can catalyze the one-pot synthesis of methyl benzylcarbamate from benzylamine, CO2 and methanol. The yield of methyl benzylcarbamate reached 92% at >99% benzylamine conversion and 92% benzylamine-based selectivity even in the absence of the dehydrating agents. The catalyst is reusable after the calcination at 873 K for 3 h. Various carbamates can be synthesized with good yield and high selectivity by the reaction of amines + CO2 + alcohols over CeO2. The main formation route of methyl benzylcarbamate is suggested to be the reaction of dimethyl carbonate or the precursor of dimethyl carbonate formation with benzylamine.
- Honda, Masayoshi,Sonehara, Satoru,Yasuda, Hiroshi,Nakagawa, Yoshinao,Tomishige, Keiichi
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scheme or table
p. 3406 - 3413
(2012/01/15)
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- Synthesis of dimethyl carbonate from methyl carbamate and methanol catalyzed by mixed oxides from hydrotalcite-like compounds
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A series of mixed oxides calcined from hydrotalcite-like compounds with different cations were prepared and their catalytic activities were studied by the synthesis of dimethyl carbonate (DMC) from methyl carbamate and methanol. Among them, ZnFe mixed oxide possessed the best catalytic ability. Furthermore, the zinc-based mixed oxides as well as the corresponding hydrotalcite-like compounds were characterized by using ICP, TGA, CO2-TPD and N2 adsorption/desorption techniques.
- Wang, Dengfeng,Zhang, Xuelan,Zhao, Wenbo,Peng, Weicai,Zhao, Ning,Xiao, Fukui,Wei, Wei,Sun, Yuhan
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experimental part
p. 427 - 430
(2010/06/20)
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- Zn/Fe mixed oxide: Heterogeneous catalyst for the synthesis of dimethyl carbonate from methyl carbamate and methanol
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A series of Zn-Fe-O mixed oxides were prepared for the synthesis of dimethyl carbonate (DMC) from methyl carbamate and methanol. X-ray diffraction revealed that zinc ferrite crystal phase appeared and changed with different Zn/Fe molar ratio. The DMC yield could reach 30.7% under suitable conditions. In addition, elemental chemical analysis and the reusability test indicated that these catalysts presented good stability.
- Wang, Dengfeng,Zhang, Xuelan,Gao, Yangyan,Xiao, Fukui,Wei, Wei,Sun, Yuhan
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scheme or table
p. 430 - 433
(2010/11/21)
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- Dibutyltin oxide catalyzed aminolysis of oxalate to carbamate, oxamate and derivatives of imidazolidine trione
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Catalytic aminolysis of oxalates by simple and substituted ureas has been shown to give carbamates, oxamates and derivatives of imidazolidine trione. Various substituted ureas and oxalates were screened to verify the applicability of the protocol. The rol
- Kunde, Lalita B.,Kalyani, Vishwanath S.,Gupte, Sunil P.
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experimental part
p. 402 - 407
(2010/08/06)
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- N-Alkyl-N-alkyloxycarbonylaminomethyl (NANAOCAM) prodrugs of carboxylic acid containing drugs
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Synthesis and hydrolysis in aqueous buffers of novel N-alkyl-N-alkyloxycarbonylaminomethyl (NANAOCAM) and N-aryl-N-alkyloxycarbonylaminomethyl (NArNAOCAM) derivatives of carboxylic acid containing drugs were carried out. The hydrolysis follows a SN1 type mechanism and is dependent on the nucleofugacity of the leaving group. Topical delivery of the NANAOCAM derivative of naproxen from IPM across hairless mice skin was examined in in vitro diffusion cell experiments. The prodrug was 4.5-fold less lipid soluble, 2.4-fold less water soluble and 3.6-fold less permeable than the parent drug.
- Majumdar, Susruta,Sloan, Kenneth B.
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p. 1447 - 1450
(2008/09/21)
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- Synthesis, hydrolyses and dermal delivery of N-alkyl-N-alkyloxycarbonylaminomethyl (NANAOCAM) derivatives of phenol, imide and thiol containing drugs
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Synthesis, characterization and hydrolysis in aqueous buffers of novel N-alkyl-N-alkyloxycarbonylaminomethyl (NANAOCAM) derivatives of substituted phenols, theophylline (Th) and 6-mercaptopurine (6MP) were carried out. The mechanism of hydrolysis was further investigated by synthesis, characterization and hydrolysis of N-aryl-N-alkyloxycarbonylaminomethyl (NArNAOCAM) derivatives of phenols. The hydrolysis follows pseudounimolecular first order kinetics and operates by way of an SN1-type mechanism. Topical delivery of selected derivatives of acetaminophen (APAP), Th and 6MP was examined in in vitro diffusion cell experiments from IPM across hairless mice skins. The prodrug of APAP and 6MP increased permeation across the skin by about 2- and 4-fold, respectively, compared to the parent drug. NANAOCAM promoieties can act as novel prodrug derivatives of phenol, imide and thiol containing drugs for enhancing topical absorption.
- Majumdar, Susruta,Sloan, Kenneth B.
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p. 3590 - 3594
(2007/10/03)
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- PROCESS FOR PREPARING CARBAMATES
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A process for the preparation of carbamates from organic urea and organic carbonate in presence of a solid base catalyst is disclosed. The process works at the milder reaction conditions and utilizes inexpensive catalysts that can be recycled several times.
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Page/Page column 17
(2008/06/13)
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- Process for preparing carbamates
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A process for the preparation of carbamates from organic urea and organic carbonate in presence of a solid base catalyst is disclosed. The process works at the milder reaction conditions and utilizes inexpensive catalysts that can be recycled several times.
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Page/Page column 7
(2008/06/13)
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- Process for making dialkyl carbonates
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A process for the production of dialkyl carbonates from the reaction of alcohol, for example C1-C3 alcohols, with urea is disclosed wherein the water and ammonium carbamates impurities in the feed are removed in a prereactor. The water is reacted with urea in the feed to produce ammonium carbamate which is decomposed along with the ammonium carbamates originally in the feed to ammonia and carbon dioxide. In addition some of the urea is reacted with the alcohol in the first reactor to produce alkyl carbamate which is a precursor to dialkyl carbonate. Dialkyl carbonates are produced in the second reaction zone. The undesired by-product N-alkyl alkyl carbamates are continuously distilled off from the second reaction zone along with ammonia, alcohol and dialkyl carbonates under the steady state reactor operation. N-alkyl alkyl carbamates can be converted to heterocyclic compounds in a third reaction zone to remove as solids from the system.
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Page/Page column 8; 9
(2008/06/13)
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- Process and catalyst for making dialkyl carbonates
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A process for producing dialkyl carbonates, such as dimethyl carbonate, from the reaction of a primary alcohol with urea in the presence of a catalyst which is a complex compound represented by R2Sn(OCH3)2.χL, wherein R=CnH2n+1, n=1 to 12, χ=1 or 2, and L is oxygen atom containing organic complexing agent which is carried out by conducting the reaction continuously under reactive distillation conditions wherein the product DMC is stripped from the reaction mixture with methanol and further including the recovery of product dimethyl carbonate (DMC) made in the process by contacting a stream containing the DMC, such as a azeotropic mixture with methanol, with diethyl oxylate under conditions of extractive distillation to selectively separate the DMC from methanol.
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Page column 8-9
(2008/06/13)
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- Carbamate synthesis by solid-base catalyzed reaction of disubstituted ureas and carbonates
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A simple and efficient methodology to prepare carbamates has been demonstrated for the first time from symmetrical ureas and organic carbonates in the presence of solid base catalysts.
- Gupte,Shivarkar,Chaudhari
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p. 2620 - 2621
(2007/10/03)
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- Conversion of carbonimidodithioates to carbamates
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Carbonimidodithioates derived from primary amines or α-amino acid esters have been converted to N-benzyloxycarbonyl derivatives under mild conditions by treatment first with sodium benzyl alcoholate and then with water. N-Benzyloxycarbonyl α-amino acids have been generated from the methyl esters by alkaline hydrolysis or from the allyl esters by Pd0-catalysed de-allylation.
- Anbazhagan, Mariappan,Reddy, T. Indrasena,Rajappa, Srinivasachari
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p. 1623 - 1627
(2007/10/03)
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- Process for making alkyl N-alkyl or N-aryl-thiocarbamates
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A process for the preparation of alkyl esters of N-alkyl or N-aryl thiocarbamic acid having the formula: STR1 wherein R is alkyl or aryl, R2 is alkyl and R1 is hydrogen or alkyl which comprises reacting the S-alkyl ester of N-alkyl or aryl dithiocarbamic acid having the formula: STR2 wherein R, R1, R2 have the meanings stated above with an appropriate alkali metal alkoxide in the presence of one or more alcoholic solvents.
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- Process for the preparation of alkyl carbamates
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The invention relates to an efficient process for the preparation of methyl methyl carbamate by reacting methyl amine or N,N'-dimethyl urea with carbon monoxide, an oxidizing agent and a monoalcohol in the presence of a catalyst system including (i) a precursor selected from the group consisting of platinum group metals and soluble compounds of platinum group metals, and (ii) a promoter comprising at least one halogen containing compound selected from the group consisting of alkali metal halides, alkaline earth metal halides, quaternary ammonium halides, oxo acids of halogen atoms and their salts, and complex compounds containing halogen ions, organic halides and halogen molecules.
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- Transesterification of alkyl carbamate to aryl carbamate : Effect of varying the alkyl group
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Phosphorus oxychloride mediated transesterification of four alkyl N-methylcarbamates to several aryl N-methylcarbamates has been studied. Best yields are obtained from benzyl N-methylcarbamate.
- Deshpande, Sunita R.,Likhite, Anjali P.,Rajappa, Srinivasachari
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p. 10367 - 10370
(2007/10/02)
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- Conversion of thiocarbamates to carbamates
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Treatment of methyl N-methylthionocarbamate (2a) with a catalytic amount of iodine or conc. H2SO4 results in the unexpected formation of the isomer, methyl N-methylthiolcarbamate (3a) in 90% yield. This has subsequently been transformed into methyl N-methylcarbamate (4a), by sodium methoxide. A curious transformation of methyl N-methyldithiocarbamate (1a) to (4a) on prolonged treatment with sodium methoxide is also discussed.
- Tandel, Sagun K.,Rajappa, Srinivasachari,Pansare, Sunil V.
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p. 7479 - 7486
(2007/10/02)
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- OZONOLYSIS OF 1-SUBSTITUTED IMIDAZOLES
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1-Substituted imidazoles was ozonolyzed cleanly without any complicated procedures into the corresponding N-acylamides, which were regarded to be much useful derivatives of either amines or acyl compounds.
- Kashima, Choji,Harada, Kaori,Hosomi, Akira
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p. 385 - 390
(2007/10/02)
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- Process for the preparation of alkyl methylcarbamates
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Alkyl carbamates are prepared by reacting a primary alkyl amine, secondary alkyl amine or dialkyl urea with carbon monoxide, an oxidizing agent and an aliphatic or alicyclic monoalcohol in the presence of a catalyst comprising (i) a platinum group metal and (ii) a halogen compound.
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- Photolysis of Dimethylcarbamoyl Azide in the Presence of a Cyclic Aminimide
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Dimethylcarbamoyl azide has been photolyzed in the presence of methyl isocyanate to produce the cyclic aminimide 1,1,4-trimethyl-1,2,4-triazolidine-3,5-dione 1,2-ylide (6) and the azo compound N-(dimethylcarbamoyl)-N,N'N'-trimethylazodicarboxamide (7).The azo compound 7 arises a photolytic reaction between dimethylcarbamoyl azide and aminimide 6.Mechanistic studies support a reaction path involving intermolecular-assisted loss of nitrogen from the azide as a result of interaction with aminimide 6.
- Gibson, Harry H.,Weissinger, Keith,Abashawl, Aida,Hall, Greg,Lawshae, Tom,et al.
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p. 3858 - 3861
(2007/10/02)
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- Fragmentation Reactions of N-Acyldienamines Giving Conjugated Enimines
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Azetidinodiazepines 1 and 2, when heated up to 200 deg C, lead to the enimines 5 and 6, respectively.The mechanism of this fragmentation was elucidated via thermolysis of the educts 8 and 10.The first one gives the enimine 5 and N-methylurethane 9 when heated in methanol.The second one gives the doubly-deuterated enimine 13, a result which shows that the N-deuteriodienamine 11 is a short-lived intermediate leading, via a many-stage prototropy, to the final enimine.Benzoylazetidinodiazepines 16 and 18, when heated in trifluoroacetic acid, lead in a similar way to the corresponding enimines 17 and 19, respectively, as well as to benzoic acid.Ammonolysis of the azetidinodiazepines 21 and 23 leads not only to the cleavage of the carbamoyl group but also to ring-opening of the β-lactam ring with formation of the dihydrodiazepines 22 and 24.Similarly, ammonolysis of the monocyclic educt 28 gives the enimine 29.
- Kiehl, Georges,Streith, Jacques,Tschamber, Theophile
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p. 2141 - 2150
(2007/10/02)
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- Photochemistry of Aliphatic Imides. Synthesis of Azetidine-2,4-diones via Photochemical Isomerization of Succinimides and N-Formyl-N-methyl α, β -Unsaturated Amides
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Photochemical reactions of alkyl-substituted succinimides and N-formyl-N-methyl α, β -unsaturated amides were studied.Photolysis of succinimide 1 gave azetidine-2,4-dione 2 together with a small amount of 3.The photoinduced ring-contraction reaction is explained in terms of a two-photon mechanism.Similarly, several other succinimide derivates photochemically gave the corresponding azetidine-2,4-diones.In addition, the photochemical cyclization of 3 to 2 was extended to the synthesis of azetidine-2,4-diones from N-formyl-N-methyl α, β -unsaturated amides.
- Maruyama, Kazuhiro,Ishitoku, Takeshi,Kubo, Yasuo
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- REACTION OF ACTIVATED AZIRIDINES WITH AMINES
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The reactions of 1-alkoxycarbonylaziridines, 1-(phenylaminocarbonyl)aziridine, and 1-arylsulfonylaziridines with ammonia and amines were investigated.It was shown that the opening of the aziridine ring in a number of cases is accompanied by aminolysis of the alkoxycarbonyl group.The dependence of the ratio of ring opening and aminolysis products on the structure of the amines is discussed.
- Baranov, S. V.,Mochalin V. B.
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p. 951 - 953
(2007/10/02)
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