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Chemistry of Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Oxidation of toluene (181) with air or oxygen in the presence of a catalyst gives benzyl alcohol (194), benzaldehyde (195), or benzoic acid (196) depending on the chemistry employed. The demand for benzoic acid far exceeds that for the other two oxidation products and so such processes are usually designed to produce mostly benzoic acid with benzaldehyde as a minor product. For the fragrance industry, benzoic acid is the precursor for the various benzoates of interest, while benzaldehyde, through aldol-type chemistry, serves as the key intermediate for cinnamate esters (such as methyl cinnamate (197)) and cinnamaldehyde (48). Reduction of the latter gives cinnamyl alcohol (49) and hence, through esterification, provides routes to all of the cinnamyl esters. Chlorination of toluene under radical conditions gives benzyl chloride (198). Hydrolysis of the chloride gives benzyl alcohol (194), which can, in principle, be esterified to give the various benzyl esters (199) of interest. However, these are more easily accessible directly from the chloride by reaction with the sodium salt of the corresponding carboxylic acid. All of these conversions are shown in Figure 6.33.
Licit and illicit drugs
Published in Jason Payne-James, Richard Jones, Simpson's Forensic Medicine, 2019
Jason Payne-James, Richard Jones
Many of these newly abused drugs belong to the chemical class known as piperazines, derived from piperazine and benzyl chloride. Piperazines were originally used as worming agents in humans and in veterinary medicine, particularly in the treatment of round worms (especially Ascaris); they paralyse the worms so they are flushed out by peristalsis. However, the medicinal use of piperazines is banned in many countries. Ironically, more than half of the cocaine sold in the USA is contaminated with levamisole, a piperazine anti-helminthic drug, which was initially withdrawn from the US market because it is known to induce bone marrow suppression. Several piperazines derivatives are now in circulation.
An Overview of Helminthiasis
Published in Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay, Medicinal Chemistry of Neglected and Tropical Diseases, 2019
Leyla Yurttaș, Betül Kaya Çavușoğlu, Derya Osmaniye, Ulviye Acar Çevik
Bephenium (14) is a quaternary ammonium derivative effective in the treatment of ascariasis, ankylostomiasis, enterobiasis, trichostrongyliasis and tricocefalosis. It is a cholinergic agonist resulting in paralysis of the parasite musculature. For the synthesis of bephenium, sodium phenolate and 2-dimethylaminoethylchloride are first reacted to give N-(2-phenoxyethyl)dimethylamine which is then treated with benzyl chloride. The resulting ammonium compound is reacted with the sodium salt of 3-hydroxy-2-naphthoic acid to afford bephenium (Vardanyan and Hruby 2006).
Arctigenin: pharmacology, total synthesis, and progress in structure modification
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Dan Wu, Lili Jin, Xing Huang, Hao Deng, Qing-kun Shen, Zhe-shan Quan, Changhao Zhang, Hong-Yan Guo
A new method involving highly regioselective and stereoselective addition of radicals to asymmetric fumarates was reported by Sibi et al.104 to exploit the synthesis of lignin natural products from common intermediates (Figure 4). Compound 30 was used as the starting material. The reaction was completed by adding benzyl 30 to CH2Cl2/THF in the presence of Sm(OTf)3 at −78 °C to obtain product 31. The required natural product was finalised by adding a second benzyl chloride solution. Consequently, 3-methoxybenzyl bromide was added after treating 31 with an equivalent amount of NaHMDS (1:1) at −78 °C for 1.25 h to give intermediate product 32, which was then cleaved effortlessly to obtain excellent yield of the key intermediate 33 using LiOH/H2O2/THF. The conversion of 33 to 34 consists of selective carboxyl reduction and lactonization. Reduction via debenzylation produced (–)-isoarctigenin (35). The reduction of compound 31 to 29a (76% in two steps) was achieved by alkylation with 3,4-dimethoxybenzyl iodide (64%). Debenzylation was then utilised to produce (–)-arctigenin.
The mercapturic acid pathway
Published in Critical Reviews in Toxicology, 2019
Patrick E. Hanna, M. W. Anders
Early studies provided indirect evidence for an N-acetylation step in mercapturic acid formation: dogs given bromobenzene (6, Figure 2) excreted S-(bromophenyl)mercapturic acid (10, Figure 2) (Baumann and Preusse 1879; Jaffé 1879). The conversion of benzyl chloride and S-(benzyl)- l-Cys (241, Figure 21) to S-(benzyl)mercapturic acid (283, Figure 23) by dogs, rabbits, and rats was also reported (Stekol 1938). When S-(4-bromophenyl)-l-Cys or S-(benzyl)-l-Cys (241, Figure 21) was given to human subjects, the corresponding mercapturic acids were excreted in the urine (Stekol 1946). The administration of several Cys S-conjugates to rats, rabbits, or guinea pigs also led to the excretion of the corresponding mercapturic acids (West and Mathura 1954; Bray et al. 1959b); moreover, incubation of the S-conjugates with liver slices also resulted in mercapturic acid formation. Elce (1970) was apparently the first to demonstrate the role of acetyl-CoA in mercapturic acid formation.
Design, synthesis and molecular mechanisms of novel dual inhibitors of heat shock protein 90/phosphoinositide 3-kinase alpha (Hsp90/PI3Kα) against cutaneous melanoma
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Feifei Qin, Yali Wang, Xian Jiang, Yujia Wang, Nan Zhang, Xiang Wen, Lian Wang, Qinglin Jiang, Gu He
Reagents and conditions: (a) NCCH2CO2Et, S8, Et3N, EtOH, reflux, 12h; (b) formamidine acetate, DMF, 100 °C,16h; (c) SO2Cl2, reflux, 4h; (d) Aromatic amine, NaH, 1,4-dioxane, 90 °C, 2 h or aliphatic amine, self-solvent, 100 °C, 1 h; (e) 9 N HCl, ethyl acetate, 25 °C, 30 min; (f) aluminum chloride, CH2Cl2, 50 °C, 24 h; (g) benzyl chloride, K2CO3, DMF; LiOH·H2O, 25 °C, 12h; (h) EDCI, HOBt, DCM, overnight and then trimethyliodosilane (TMIS), 25 °C, 24 h or H2, 10% Pd/C, 25 °C, 24 h.