188425-85-6Relevant articles and documents
Preparation method of acrylamido
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, (2022/01/04)
The present invention relates to a method for preparing a pyrimidine, 9-fluorenone as raw material, by open loop, acid chloride, amidation, chlorination, Hofmann (Hofmann) rearrangement degradation to give 2-(4'-chlorophenyl) aniline, and then condensed with 2-chloronicotinamide to give the product acetoimide, the present invention also relates accordingly to the intermediates 4'-chloro-2-bibenzamide and 4'-chloro-2-aminobiphenyl preparation method. The method of the present invention can obtain the target product with high yield, high purity, and can reduce costs while reducing environmental harm.
Pd-Catalysed Suzuki-Miyaura cross-coupling of aryl chlorides at low catalyst loadings in water for the synthesis of industrially important fungicides
Goetz, Roland,Hashmi, A. Stephen K.,Orecchia, Patrizio,Petkova, Desislava Slavcheva,Rominger, Frank,Schaub, Thomas
, p. 8169 - 8180 (2021/11/01)
The Suzuki-Miyaura coupling reaction of electron-poor aryl chlorides in the synthesis of crop protection-relevant active ingredients in water is disclosed. Optimisation of the reaction conditions allowed running the reaction with 50 ppm of Pd-catalyst loading without an additional organic solvent in the cross-coupling reaction step in short reaction times. The system was optimised for the initial cross-coupling step of the large scale produced fungicides Boscalid, Fluxapyroxad and Bixafen up to 97% yield. It is also shown that the Suzuki-Miyaura reaction can be easily scaled up to 50 g using a simple product separation and purification using environmentally benign solvents in the work-up. To show the usability of this method, it was additionally applied in the three-step synthesis of the desired active ingredients.
Synthesis and process optimization of Boscalid by catalyst Pd-PEPPSI-IPrDtBu-An
Xu, Jian,Lan, Xiao-Bing,Xia, Lin-Jian,Yang, Yi,Cao, Gao
, p. 247 - 256 (2021/05/06)
The purpose of this research was to reduce the amount of noble metal palladium catalyst and improve the catalytic performance in the Suzuki–Miyaura cross-coupling reaction, which is the key step in the synthesis of Boscalid. Taking o-bromonitrobenzene and p-chlorophenylboronic acid as raw materials, three kinds of Pd-PEPPSI-IPr catalysts were synthesized and employed in the Suzuki reaction, and then the biaryl product was subjected to reduction and condensation reaction to give Boscalid. Under the optimal reaction conditions, the result showed that the catalytic system exhibits highest catalytic efficiency under aerobic conditions, giving the 2-(4-chlorophenyl)nitrobenzene in over 99 % yield. Moreover, the Pd-PEPPSI-IPrDtBu-An catalyst was minimized to 0.01 mol%. The synthesis process was mild, the post-treatment was simple, and the production cost was reduced, which makes it suitable for industrial production.
Highly efficient palladium-catalyzed cross-coupling of diarylborinic acids with arenediazoniums for practical diaryl synthesis
Wang, Fengze,Wang, Chen,Sun, Guoping,Zou, Gang
, (2019/12/25)
A highly efficient cross-coupling of cost-effective diarylborinic acids with both isolatable and latent arenediazoniums, i.e. tetrafluoroborates and aryltriazenes, respectively, has been developed with a practical palladium catalyst system under base-free conditions in open flask at room temperature. A variety of electronically and sterically various biaryls, in particular, those bearing a coordinative ortho-substituent, could be obtained in good to excellent yields by using 0.3 mol% palladium acetate as catalyst. Features of the protocol including cost-effectiveness of diarylborinic acids, efficacy to heteroatom ortho-substituted substrates and high chemoselectivity to aryl chlorides have been clearly demonstrated in practical synthesis of fungicide Boscalid.
A Sustainable 1-Pot, 3-Step Synthesis of Boscalid Using Part per Million Level Pd Catalysis in Water
Takale, Balaram S.,Thakore, Ruchita R.,Mallarapu, Rushil,Gallou, Fabrice,Lipshutz, Bruce H.
, p. 101 - 105 (2019/12/30)
Boscalid is an active ingredient in several fungicides marketed by the BASF. Literature approaches use multipot processes, organic solvents, and unsustainable levels of palladium catalysis. Herein is disclosed a 1-pot, 3-step route using nanomicelles in water as the reaction medium and a very low loading (700 ppm or 0.07 mol %) of costly and endangered Pd. The sequence developed involves an initial Suzuki-Miyaura cross-coupling, the product from which is not isolated. The second step relies on a carbonyl iron powder (CIP) reduction of the aryl nitro group, followed by the third and final step involving an acylation with the required 2-chloronicotinyl chloride. The overall isolated yield for these three steps is 83%.
Clickable coupling of carboxylic acids and amines at room temperature mediated by SO2F2: A significant breakthrough for the construction of amides and peptide linkages
Wang, Shi-Meng,Zhao, Chuang,Zhang, Xu,Qin, Hua-Li
supporting information, p. 4087 - 4101 (2019/04/30)
The construction of amide bonds and peptide linkages is one of the most fundamental transformations in all life processes and organic synthesis. The synthesis of structurally ubiquitous amide motifs is essential in the assembly of numerous important molecules such as peptides, proteins, alkaloids, pharmaceutical agents, polymers, ligands and agrochemicals. A method of SO2F2-mediated direct clickable coupling of carboxylic acids with amines was developed for the synthesis of a broad scope of amides in a simple, mild, highly efficient, robust and practical manner (>110 examples, >90% yields in most cases). The direct click reactions of acids and amines on a gram scale are also demonstrated using an extremely easy work-up and purification process of washing with 1 M aqueous HCl to provide the desired amides in greater than 99% purity and excellent yields.
Catalyst shuttling enabled by a thermoresponsive polymeric ligand: Facilitating efficient cross-couplings with continuously recyclable ppm levels of palladium
Wang, Erfei,Chen, Mao
, p. 8331 - 8337 (2019/09/30)
A polymeric monophosphine ligand WePhos has been synthesized and complexed with palladium(ii) acetate [Pd(OAc)2] to generate a thermoresponsive pre-catalyst that can shuttle between water and organic phases, with the change being regulated by temperature. The structure of the polymeric ligand was confirmed with matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and size-exclusion chromatography (SEC) analysis, as well as nuclear magnetic resonance (NMR) measurements. This polymeric metal complex enables highly efficient Pd-catalyzed cross-couplings and tandem reactions using 50 to 500 ppm palladium, and this can facilitate reactions that are tolerant to a broad spectrum of (hetero)aryl substrates and functional groups, as demonstrated with 73 examples with up to 99% isolated yields. Notably, 97% Pd remained in the aqueous phase after 10 runs of catalyst recycling experiments, as determined via inductively coupled plasma-atomic emission spectrometry (ICP-AES) measurements, indicating highly efficient catalyst transfer. Furthermore, a continuous catalyst recycling approach has been successfully developed based on flow chemistry in combination with the catalyst shuttling behavior, allowing Suzuki-Miyaura couplings to be conducted at gram-scales with as little as 10 ppm Pd loading. Given the significance of transition-metal catalyzed cross-coupling and increasing interest in sustainable chemistry, this work is an important step towards the development of a responsive catalyst, in addition to having high activity, by tuning the structures of the ligands using polymer science.
Process for synthesizing boscalid
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, (2019/05/02)
The invention discloses a process for synthesizing boscalid. The process comprises the following steps: (1) coupling o-chlorobenzonitrile with benzene to obtain 2-cyanobiphenyl, then carrying out chlorination, reduction and salt formation purification to obtain 4'-chloro-2-aminobiphenyl hydrochloride; (2) carrying out condensation reaction on the prepared 4'-chloro-2-aminobiphenyl hydrochloride and 2-chloronicotinoyl chloride to obtain the boscalid. The process for synthesizing the boscalid has the advantages of simple synthesis process, no need of complex aftertreatment, cheap and easily available basic chemical raw materials, and suitability for industrial production.
Method for preparing boscalid
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, (2019/02/04)
The invention relates to a method for preparing boscalid. The method comprises the following steps: sequentially preparing intermediates 2-(4-chlorophenyl)aniline and 2-chloronicotinyl chloride by means of a chlorination/ring opening reaction, an amidation reaction, Hofmann rearrangement and an acylating chlorination reaction, and enabling the obtained intermediates to be subjected to a syntheticreaction to obtain the boscalid. The method for preparing the boscalid has the advantages of being easy in obtaining of raw materials, easy in creation of reaction conditions, little in environmentalpollution and high in yield, thus being suitable for large-scale production.
A new,: Substituted palladacycle for ppm level Pd-catalyzed Suzuki-Miyaura cross couplings in water
Takale, Balaram S.,Thakore, Ruchita R.,Handa, Sachin,Gallou, Fabrice,Reilly, John,Lipshutz, Bruce H.
, p. 8825 - 8831 (2019/10/16)
A newly engineered palladacycle that contains substituents on the biphenyl rings along with the ligand HandaPhos is especially well-matched to an aqueous micellar medium, enabling valued Suzuki-Miyaura couplings to be run not only in water under mild conditions, but at 300 ppm of Pd catalyst. This general methodology has been applied to several targets in the pharmaceutical area. Multiple recyclings of the aqueous reaction mixture involving both the same as well as different coupling partners is demonstrated. Low temperature microscopy (cryo-TEM) indicates the nature and size of the particles acting as nanoreactors. Importantly, given the low loadings of Pd invested per reaction, ICP-MS analyses of residual palladium in the products shows levels to be expected that are well within FDA allowable limits.
