scholarly journals A Facile Synthesis of 3-(Chloromethyl)-2-methyl-1,1′-biphenyl

2019 ◽  
Vol 31 (12) ◽  
pp. 3009-3011
Author(s):  
Lele Zhang ◽  
Songbo Cheng ◽  
Hang Hu ◽  
Defeng Xu
Keyword(s):  
High Risk ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
High Yield ◽  
Synthesis Process ◽  
Lithium Aluminum ◽  
Efficient Synthesis ◽  
Facile Synthesis ◽  
Synthetic Process ◽  
Safety Issues

3-(Chloromethyl)-2-methyl-1,1′-biphenyl is a key intermediate for the preparation of bifenthrin, an insecticide which belongs to pyrethroid. The traditional synthetic process of 3-(chloromethyl)-2-methyl- 1,1′-biphenyl is complicated and involves high-toxic and high-risk reagents such as thionyl chloride, lithium aluminum hydride and methyl iodide, which causes significant environmental problems and safety issues. Herein, a facile and efficient synthesis process of 3-(chloromethyl)-2- methyl-1,1′-biphenyl was developed. The synthetic process is shortened from 6 steps to only 4 steps and avoids the use of high-toxic and high-risk reagents. Moreover, 3-(chloromethyl)-2-methyl-1,1′-biphenyl can be obtained by simple purification process in high yield (73.9 %). Compared with the traditional synthetic process, the synthetic process of 3-(chloromethyl)-2-methyl-1,1′-biphenyl reported here is more environmental friendly and efficient.

ANTINEOPLASTIC AGENTS: XI. N-BIS(2-BROMOETHYL)AMINES

1964 ◽  
Vol 42 (7) ◽  
pp. 1699-1706 ◽  
Author(s):  
George R. Pettit ◽  
Maurice R. Chamberland ◽  
David S. Blonda ◽  
Martyn A. Vickers
Keyword(s):  
Exchange Reaction ◽  
Antineoplastic Agents ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Efficient Synthesis ◽  
Nitrogen Mustards ◽  
Hydride Reduction ◽  
Halogen Exchange ◽  
Convenient Route

A novel halogen exchange reaction was found to accompany condensation of an acyl chloride with N-bis(2-bromoethyl)amine. Reaction between an acyl bromide and N-bis(2-bromoethyl)amine, however, gave the expected N-bis(2-bromoethyl)amide. A number of N-alkyl-N-bis(2-bromoethyl)amines were prepared by lithium aluminum hydride reduction of the corresponding N-bis(2-bromoethyl)amides. The overall transformation from N-bis(2-bromoethyl)amine presents a convenient route to certain bromo nitrogen mustards. An efficient synthesis of N-bis(2-iodoethyl)amine hydroiodide is also described.

Stereoselective Total Synthesis of Copa and Ylango Sesquiterpenoids: (+)-Copacamphor, (+)-Copaborneol, (+)-Copaisoborneol, (−)-Ylangocamphor, (−)-Ylangoborneol, (−)-Ylangoisoborneol

1975 ◽  
Vol 53 (19) ◽  
pp. 2838-2848 ◽  
Author(s):  
Edward Piers ◽  
Ronald W. Britton ◽  
M. Bert Geraghty ◽  
Robert J. Keziere ◽  
Fusao Kido
Keyword(s):  
Total Synthesis ◽  
Liquid Ammonia ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
High Yield ◽  
Lithium Aluminum ◽  
Alkylation Product ◽  
Intramolecular Alkylation ◽  
Enolate Anion ◽  
Stereoselective Syntheses

Efficient, stereoselective syntheses of the tricyclic sesquiterpenoids (+)-copacamphor (3), (+)-copaborneol (4), (+)-copaisoborneol (5), (−)-ylangocamphor (6), (−)-ylangoborneol (7), and (−)-ylangoisoborneol (8) are described. Conversion of the keto acetate 9 (previously synthesized from the dione 1) into the keto tosylate 17 was accomplished via an eight-step sequence. Intramolecular alkylation of 17 afforded, in high yield, (+)-copacamphor (3), which had previously been converted into the corresponding alcohols 4 and 5 by Kolbe-Haugwitz and Westfelt. Alkylation of the enolate anion of the bicyclic dione 2 with 2-bromopropane in hexamethylphosphoramide gave mainly the O-alkylation product 19. Conversion of 19 into the keto mesylate 29 was carried out in 5 synthetic steps. Intramolecular alkylation of 29 afforded (−)-ylangocamphor (6). Reduction of the latter with calcium in liquid ammonia gave (−)-ylangoborneol (7), while reduction with lithium aluminum hydride yielded (−)-ylangoisoborneol (8).

scholarly journals Multistep batch-flow hybrid synthesis of a terbinafine precursor

2021 ◽  
Author(s):  
Tamás Hergert ◽  
Béla Mátravölgyi ◽  
Róbert Örkényi ◽  
János Éles ◽  
Ferenc Faigl
Keyword(s):  
Methyl Ether ◽  
Lithium Salt ◽  
Scale Up ◽  
Hybrid Process ◽  
High Yield ◽  
Grignard Reaction ◽  
Efficient Synthesis ◽  
Synthetic Process ◽  
Synthesis Route ◽  
Selective Addition

AbstractA three-step batch-flow hybrid process has been developed for an expeditious synthesis of the enynol key intermediate of antifungal terbinafine. This procedure involves consecutive organometallic steps without the necessity of any in-line purification: after a metalation by n-butyllithium, a selective addition of the lithium salt was elaborated followed by a Grignard reaction resulting in a high yield of 6,6-dimethylhept-1-en-4-yn-3-ol. Moreover, as an alternative to tetrahydrofuran, cyclopentyl methyl ether was used as solvent implementing a safe, sustainable, yet selective synthetic process. Even on a laboratory-scale, the optimized batch-flow hybrid process had a theoretical throughput of 41 g/h. Furthermore, the newly developed process provides an efficient synthesis route to the key-intermediate, while making acrolein obsolete, minimizing side-products, and enabling safe and convenient scale-up.

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