- Synthesis of task-specific imidazolium ionic liquid as an efficient catalyst in acetylation of alcohols, phenols, and amines
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Herein, we report the synthesis of task-specific amino-functionalized imidazolium ionic liquid, acetate1-(2-tert-butoxycarbonylamino-ethyl)-3-methyl-3H-imidazol-1-ium; (Boc-NH-EMIM.OAc), as an efficient catalyst for the acetylation of alcohols, phenols, and amines in the presence of acetic anhydride (acetylating reagent). Remarkably, acetic anhydride in the presence of 10?molpercent of catalyst (Boc-NH-EMIM.OAc) under solvent-free conditions showed excellent acetylation activity in shorter duration of time. On the basis of this, a general procedure for acetylation of alcohols, phenols, and amines has been developed. The ionic liquid (Boc-NH-EMIM.OAc) can be readily recovered and reused successfully up to four consecutive cycles without any significant loss of its catalytic activity. We have been able to show that this acetylating method has many advantages. It gives high yields, takes shorter time, and develops the possibility of benign environmental-friendly process.
- Chaubey, Snehkrishn A.,Mishra, Roli
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p. 3259 - 3268
(2020/04/17)
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- Method for synthesizing lithocholic acid from hyodeoxycholic acid as raw material
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The invention discloses a method for synthesizing a lithocholic acid from a hyodeoxycholic acid as the raw material. The hyodeoxycholic acid is used as the starting material, the lithocholic acid is produced through the seven reaction steps of 24-carboxylesterification, carboxylation of 3alpha-hydroxyl and 6alpha-hydroxyl through oxidation, selective reduction, acylation, hydrazone formation, hydrazoneremoval, and hydrolysis. The starting material is cheap and easy to get, no hydrazine hydrate is used in the synthesis process, the technological conditions for synthesis are safe, environmentally friendly and mild, the total yield is relatively high, and the method is suitable for industrial production.
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Paragraph 0021; 0026
(2019/01/23)
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- Protection of COOH and OH groups in acid, base and salt free reactions
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We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction.
- Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
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supporting information
p. 1444 - 1447
(2018/04/12)
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- The synthesis and antitumor activity of lithocholic acid and its derivatives
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In this paper, a new and concise synthetic route of lithocholic acid (LCA) using commercially available steroid source deoxycholic acid is reported. A series of amide derivatives of LCA were also synthesized and investigated for their activity against the growth of MCF-7 and MCF-7/ADR cells using the sulforhodamine B assay. For MCF-7, the most potent compound 20 showed a 20-fold higher antitumor activity than LCA. For MCF-7/ADR, the most potent compound 24 showed a 22-fold higher antitumor activity than LCA. The transwell migration assay of 20 was evaluated on MDA-MB-231 cells. The colony formation and apoptosis assays of 20 were performed on MCF-7 and MCF-7/ADR cell lines.
- He, Xiao-Long,Xing, Yajing,Gu, Xiang-Zhong,Xiao, Jie-Xin,Wang, Ying-Ying,Yi, Zhengfang,Qiu, Wen-Wei
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- PROCESS AND INTERMEDIATES FOR THE 6,7-ALPHA-EPOXIDATION OF STEROID 4,6-DIENES
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The invention relates to a process for preparing a compound of general formula (la): wherein R2, Y, R4and R5are as defined herein, wherein the epoxidation is conducted using an oxidant and methyltrioxorhenium as a catalyst (MeReO3). The invention also relates to certain compounds per se.The compounds are intermediates in the synthesis of synthetic bile acids.
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Page/Page column 69
(2017/12/16)
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- Synthesizing method of lithocholic acid
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The invention discloses a synthesizing method of lithocholic acid. The synthesizing method is characterized in that deoxycholic acid is used as the raw material, and the deoxycholic acid is subjected to reactions such as methyl esterification protection, acetic anhydride protection of 3 hydroxyl groups, dewatering, hydrogenation and hydrolysis to synthesize the lithocholic acid. The synthesizing method is simple in step, few in side reaction, high in yield, easy in raw material obtaining, suitable for industrial production, and capable of solving the problems that the prior art is excessively high in synthesizing cost, low in yield and not suitable for large-scale industrial production.
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Paragraph 0054; 0055
(2016/12/22)
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- 6-ALKYL-7-HYDROXY-4-EN-3-ONE STEROIDS AS INTERMEDIATES FOR THE PRODUCTION OF STEROIDAL FXR MODULATORS
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The invention relates to compounds of formula (I), wherein R1, R2, Y, R4 and R5 are as defined herein. The compounds are intermediates in the synthesis of synthetic bile acids.
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- Lithocholic acid and derivatives: Antibacterial activity
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In order to develop bioactive lithocholic acid derivatives, we prepared fifteen semi-synthetic compounds through modification at C-3 and/or C-24. The reactions showed yields ranging from 37% to 100%. The structures of all compounds obtained were identified on the basis of their spectral data (IR, MS, 1D- and 2D-NMR). The activity of lithocholic acid and derivatives was evaluated against the growth of Escherichia coli, Staphylococcus aureus, Bacillus cereus and Pseudomonas aeruginosa. The derivative 3α-formyloxy-5β-cholan-24-oic acid (LA-06) showed the best activity, with MIC values of 0.0790 mM against E. coli (Ec 27) and B. cereus in both cases, and 0.0395 mM against S. aureus (ATCC 12692). Lithocholic acid and the derivatives with MIC ≤ 1.2 mM were evaluated on the susceptibility of some bacterial pathogens to the aminoglycoside antibiotics neomycin, amikacin and gentamicin was evaluated. There are no previously reported studies about these compounds as modifiers of the action of antibiotics or any other drugs.
- Do Nascimento, Patrícia G.G.,Lemos, Telma L.G.,Almeida, Macia C.S.,De Souza, Juliana M.O.,Bizerra, Ayla M.C.,Santiago, Gilvandete M.P.,Da Costa, José G.M.,Coutinho, Henrique D.M.
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