542-08-5Relevant articles and documents
Enantioselective aldol-type reaction using diketene
Kawase, Takahiro,Takizawa, Shinobu,Jayaprakash, Doss,Sasai, Hiroaki
, p. 4487 - 4492 (2004)
An aldol-type reaction catalyzed by a Ti-(S)-BINOL complex using with a diketene as substrate is described herein. The complex derived from 1.0 molar equivalent of Ti(O-i-Pr)4 and 2.0 molar equivalents of (S)-BINOL gave (5)-isopropyl 5-hydroxy-7-phenyl-3-oxo-6-heptenoate with high enantioselectivity.
Br?nsted acidic cellulose-PO3H: An efficient catalyst for the chemoselective synthesis of fructones and trans-esterification via condensation of acetoacetic esters with alcohols and diols
Naikwadi, Dhanaji R.,Singh, Amravati S.,Biradar, Ankush V.
, (2021/10/04)
Cellulose is the most abundant organic source and has expedient a great deal of interest as renewable and emerged as sustainable feedstock. The functionalization of cellulose as designed catalytic system intriguing furnished to the production of fine chemicals. Herein, we synthesized an environmental friendly solid acid catalyst by functionalizing cellulose with phosphoric acid (PO3H). The successful functionalization of cellulose with PO3H was confirmed by 31P NMR, ICP-OES, FE-SEM, and XPS analysis. ICP-OES revealed the presence of phosphorus content of ～1.0 wt. % on the catalyst's surface while elemental mapping by FESEM and XPS shows a uniform distribution of phosphorus over the material. The synthesized solid acid catalyst was utilized for condensation of diols with acetoacetic esters in solvent-free conditions to synthesize fine chemicals. The present approach not only circumvented the one-step protection and other products but more fascinatingly provided trans-esterification of acetoacetic esters with diols and n-alcohols. The catalyst was successfully used for chemoselective protection on ethyl acetoacetate with 1, 2 diols to essential fructone molecule with ～100% conversion and 99% selectivity. The results suggested that the catalyst has the advantage over commercial solid acid heterogeneous and homogeneous catalysts.
Revisiting ageless antiques; synthesis, biological evaluation, docking simulation and mechanistic insights of 1,4-Dihydropyridines as anticancer agents
Sidhom, Peter A.,El-Bastawissy, Eman,Salama, Abeer A.,El-Moselhy, Tarek F.
supporting information, (2021/06/21)
The historic DHP nucleus was serendipitously discovered by Arthur Hantzsch about 130 years ago and is still considered a hidden treasure for various pharmacological activities. Twenty-one DHP analogues were synthesized using the expedient one pot Hantzsch synthesis for screening as anticancer agents. Initially, the in vitro anti-proliferative single dose against a panel of 18 cancer cell lines showed that compounds 11b and 8f were the superlative candidates regarding their antitumor effect (GI% mean = 66.40% and 50.42%, correspondingly) compared to cisplatin (GI% mean = 65.58%) and doxorubicin (GI% mean = 74.56%). Remarkably, compound 11b showed a remarkable MDA-MB-468 anticancer activity (GI%=80.81%), higher than cisplatin (64.44%) and doxorubicin (76.72%), as well as strong antitumor activity against lung cancer A549 (GI%= 83.02%), more powerful than both cisplatin and doxorubicin. Compound 11b exhibited an exceptional anticancer activity against lung cancer cell line (A549) as its GI50 in nanomolar was (540 nM) with a 9-fold increase greater than cisplatin (GI50 = 4.93 μM) and with a selectivity index = 131 to cancer cells over normal cells. Further mechanistic investigations proved that DHPs anticipate simultaneously TOPI and RTKs (VEGFR-2, HER-2 and BTK) which can stimulate BAX/BAK and the executioner caspases via rtPCR studies.
Nimodipine impurity IV reference substance as well as preparation method and application thereof
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Paragraph 0051-0052, (2020/11/22)
The invention discloses a nimodipine impurity IV reference substance and a preparation method thereof. The method includes the steps that diketene, ethyl alcohol and triethylamine are taken and addedinto a container to be heated and cooled, reaction liquid is washed with water, washing liquid is discarded, anhydrous sodium sulfate is added and placed overnight, filtrate is obtained after filtration, ammonia gas is introduced into the filtrate until the filtrate is saturated, and the nimodipine impurity IV reference substance is obtained; and after the reaction is finished, m-nitrobenzaldehyde, methoxyethyl acetoacetate and ethanol are added, heating refulx is performed, the mixture is cooled and filtered, the solvent is removed through volatilization in a water bath to obtain a yellow viscous liquid, and recrystallization is carried out to obtain a yellow acicular crystal, namely the nimodipine impurity IV reference substance. The invention also discloses an application of the nimodipine impurity IV reference substance in nimodipine tablet consistency evaluation. According to the preparation method, the impurity IV can be prepared in a general analysis laboratory, special preparation equipment is not needed, the operation is simple, the purity of the obtained impurity reference substance can reach 98.4%, the purity requirement of the reference substance is met, and the preparation method can be used for consistency evaluation of the variety.
N, N’-dimethyl formamide (DMF) mediated Vilsmeier–Haack adducts with 1,3,5-triazine compounds as efficient catalysts for the transesterification of β-ketoesters
Chityala, Yadaiah,Duguta, Govardhan,Kamatala, Chinna Rajanna,Muddam, Bhooshan,Mukka, Satish Kumar
supporting information, p. 1641 - 1655 (2020/05/25)
N, N’-dimethyl formamide (DMF) mediated Vilsmeier–Haack (VH) adducts with 1,3,5-triazine compunds such as trichloroisocyanuric acid (TCCA) and trichlorotriazine (TCTA) were prepared by replacing classical oxy chlorides POCl3, and SOCl2, which were explored as efficient catalysts for the transesterification of β-ketoesters. The prepared (TCCA/DMF) and (TCTA/DMF) adducts improved greenery of the classical Vilsmeier–Haack reagents (POCl3/DMF), and (SOCl2/DMF), and demonstrated their better efficient catalytic ativity. Reaction times were in the range: 3.5 to 6.5 hr (SOCl2/DMF); 2.8–5.2 hr (POCl3/DMF); 2.5–5.2 hr (TCCA/DMF) and 2.5–5.0 hr (TCTA/DMF) catalytic systems. Ultrasonically (US) assisted protocols with these reagents further reduced the reaction times (two to three times), while microwave assisted (MW) protocols with these reagents were much more effective. The reactions could be completed in only few seconds (less than a minute) in MWassisted protocols as compared to US assited reactions, followed by good product yields.
Design, synthesis, and bioactivity of dihydropyrimidine derivatives as kinesin spindle protein inhibitors
Tawfik, Haytham O.,El-Hamamsy, Mervat H.,Sharafeldin, Nabaweya A.,El-Moselhy, Tarek F.
, (2019/11/11)
A series of twenty-one 3,4-dihydropyrimidine derivatives bearing the heterocyclic 1,3-benzodioxole at position 4 in addition to different substituents at positions 2, 3 and 5 were designed and synthesized as monastrol analogs. The novel synthesized compounds were screened for their cytotoxic activity towards 60 cancer cell lines according to NCI (USA) protocol. Compounds 10b and 15 showed the best antitumor activity against most cell lines. Compound 15 was subsequently tested in 5-doses mode and displayed high selectivity towards CNS, prostate and leukemia subpanel with selectivity ratios of 22.30, 15.38 and 12.56, respectively at GI50 level. The IC50 of compounds 9d, 10b, 12, 15 and 16 against kinesin enzyme were 3.86 ± 0.12, 10.70 ± 0.35, 3.95 ± 0.12, 4.36 ± 0.14, and 14.07 ± 0.45 μM respectively, while the prototype compound, monastrol, reported IC50 value of 20 ± 0.42 μM. The safest compound among test compounds against normal cell line (HEK 293) is 10b with IC50 value of 62.02 ± 2.42 μM/ml in comparison to doxorubicin (IC50 = 11.34 ± 0.44 μM/ml). Cell cycle analysis of SNB-75 cells treated with compound 15 showed cell cycle arrest at G2/M phase. Further, the assay of levels of active caspase-3 and caspase-9 was investigated. Moreover, Molecular docking of compounds, 9d, 10b, 12, 15, 16, monastrol and mon-97 was performed to study the interaction between inhibitors and the kinesin spindle protein allosteric binding site.
General [4 + 1] Cyclization Approach to Access 2,2-Disubstituted Tetrahydrofurans Enabled by Electrophilic Bifunctional Peroxides
Gao, Min,Zhao, Yukun,Zhong, Chen,Liu, Shengshu,Liu, Pengkang,Yin, Qi,Hu, Lin
supporting information, p. 5679 - 5684 (2019/08/01)
A general [4 + 1] cyclization reaction of carbonyl nucleophiles with 2-iodomethylallyl peroxides, which function as unique electrophilic oxygen synthons, for the synthesis of a broad range of 2,2-disubstituted tetrahydrofurans is achieved under operationally simple conditions. The unprecedented asymmetric version of such reaction is also realized via chiral auxiliary-assisted cyclization, thus providing a distinct approach to access chiral tetrahydrofurans with high diastereoselectivities. The new method can be applied to the synthesis of core structure of posaconazole drug.
Preparation technology of isopropyl acetoacetate
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Paragraph 0038; 0039; 0040; 0042; 0044; 0046; 0048, (2018/05/03)
The invention discloses a preparation technology of isopropyl acetoacetate. The preparation technology comprises the following steps: adding isopropanol and a catalyst into a reaction vessel, whereinthe catalyst is selected from aliphatic amine catalysts or tertiary amine catalysts; or the catalyst is prepared by mixing one or more of the aliphatic amine catalysts and the tertiary amine catalysts; raising the temperature to 20 to 100 DEG C, dropwise adding diketene, controlling the reaction temperature in the reaction process at 20 to 150 DEG C; after dropwise adding is finished, controllingthe temperature at 20 to 150 DEG C and carrying out thermal insulation for 0.5 to 6 hours, thus obtaining raw isopropyl acetoacetate, wherein the molar ratio of the isopropanol to the diketene is (1 to 1.8) to 1 and the adding amount of the catalyst is 0.1 to 1 weight percent of the total amount. By adopting a combined amine catalyst to carry out esterification reaction of the diketene and the isopropanol, the influence of steric hindrance of the isopropanol is reduced and the yield of esterification is improved; meanwhile, the difficulty of subsequent separation is reduced. After distillation, the yield of esterification liquid reaches 95 percent and the content of the esterification liquid reaches 99 percent or above.
Prussian blue as an efficient catalyst for rate accelerations in the transesterification of β-ketoesters
Srinivas,Rajanna,Krishnaiah,Kumar, M. Satish,Reddy, J. Narender
, p. 1212 - 1220 (2014/04/17)
Prussian blue triggered transesterification of ethylacetoacetate with various alcohols underwent efficiently. The reaction is mild, eco-friendly, and selective with good yields. The proposed reaction pathway depicts the formation of an intermediate by the interaction of β-ketoesters with catalytic site of the Prussian blue, followed by nucleophilic attack of the alcohol at the electrophilic center followed by successive elimination of the proton to give the product. Observed longer reaction times under conventional conditions reduced amazingly under sonication and microwave irradiation followed enhanced yield of products.
AgOTf-catalyzed transesterification of β-keto esters
Das, Rima,Chakraborty, Debashis
experimental part, p. 140 - 144 (2012/05/20)
AgOTf proved to be an effective catalyst for the transesterification of β-keto esters with primary, secondary and tertiary alcohols. The products were obtained in high yield within a reasonable reaction time period. The kinetics of the transesterification reaction were also studied and the reaction was found to follow second-order kinetics. Copyright
