- An expeditious synthesis of tamoxifen, a representative SERM (selective estrogen receptor modulator), via the three-component coupling reaction among aromatic aldehyde, cinnamyltrimethylsilane, and β-chlorophenetole
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Two new synthetic pathways to the anti-cancer agent tamoxifen and its derivatives were developed. The first route involved the aldol reaction of benzyl phenyl ketone with acetaldehyde followed by Friedel-Crafts substitution with anisole in the presence of Cl2Si(OTf)2 to produce 1,1,2-triaryl-3-acetoxybutane, a precursor of the tamoxifen derivatives. The second one utilized the novel three-component coupling reaction among aromatic aldehydes, cinnamyltrimethylsilane, and aromatic nucleophiles using HfCl4 as a Lewis acid catalyst to produce 3,4,4-triarylbutene, that is also a valuable intermediate of the tamoxifen derivatives. The former strategy requires a total of 10 steps from the aldol formation to the final conversion to tamoxifen, whereas the latter needs only three or four steps to produce tamoxifen and droloxifene including the installation of the side-chain moiety and the base-induced double-bond migration to form the tetra-substituted olefin structure. This synthetic strategy seems to serve as a new and practical pathway to prepare not only the tamoxifen derivatives but also the other SERMs (selective estrogen receptor modulators) including estrogen-dependent breast cancer and osteoporosis agents.
- Shiina, Isamu,Sano, Yoshiyuki,Nakata, Kenya,Suzuki, Masahiko,Yokoyama, Toshikazu,Sasaki, Akane,Orikasa, Tomoko,Miyamoto, Tomomi,Ikekita, Masahiko,Nagahara, Yukitoshi,Hasome, Yoshimune
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p. 7599 - 7617
(2008/03/14)
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- Short-step synthesis of droloxifene via the three-component coupling reaction among aromatic aldehyde, cinnamyltrimethylsilane, and β-chlorophenetole
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A short-step route for the preparation of droloxifene has been established via the novel three-component coupling reaction among 3-pivaloyloxybenzaldehyde, cinnamyltrimethylsilane, and β-chlorophenetole, the successive installation of the side-chain part, and the base-induced migration of the double bond. The present synthesis of tetra-substituted ethylene moieties is a widely applicable strategy for producing a variety of SERMs (selective estrogen receptor modulators) and SARMs (selective androgen receptor modulators), such as tamoxifen, raloxifene, and other compounds that can lead to new drugs.
- Sano, Yoshiyuki,Shiina, Isamu
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p. 1631 - 1635
(2007/10/03)
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- Nitrate prodrugs able to release nitric oxide in a controlled and selective way and their use for prevention and treatment of inflammatory, ischemic and proliferative diseases
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New pharmaceutical compounds of general formula (I): F-(X)q where q is an integer from 1 to 5, preferably 1; -F is chosen among drugs described in the text, -X is chosen among 4 groups -M, -T, -V and -Y as described in the text. The compounds of general formula (I) are nitrate prodrugs which can release nitric oxide in vivo in a controlled and selective way and without hypotensive side effects and for this reason they are useful for the preparation of medicines for prevention and treatment of inflammatory, ischemic, degenerative and proliferative diseases of musculoskeletal, tegumental, respiratory, gastrointestinal, genito-urinary and central nervous systems.
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- New highly stereoselective synthesis of (E)-droloxifene via selective protection of 3,4'-dihydroxybenzophenone and McMurry reaction
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A new, highly stereoselective synthesis of (E)-droloxifene is reported. Deprotection of 3,4'-dimethoxybenzophenone and selective pivaloylation of the 3'-phenolic position gave 4-hydroxy-3'-(trimethylacetoxy)benzophenone. A McMurry reaction between the preceding benzophenone and propiophenone gave the (E)-olefin as a major product (14:1 E/Z ratio in crude reaction), which was then alkylated with 2-dimethylaminoethyl chloride and deprotected to yield (E)-droloxifene with a > 100:1 E/Z ratio (5 steps, 13%). Attempts to use this strategy as a suitable stereoselective method to obtain (Z)- droloxifene were not successful. (C) 2000 Elsevier Science Ltd.
- Gauthier, Sylvain,Sancéau, Jean-Yves,Mailhot, Josée,Caron, Brigitte,Cloutier, Julie
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p. 703 - 709
(2007/10/03)
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- Preparation of grignard reagents: FTIR and calorimetric investigation for safe scale-up
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Preparation of Grignard reagents from organic halides and magnesium pose potential safety hazards on scale-up due to their high exothermic potential which can lead to overpressurization, discharge of contents, or explosion. One of the main challenges arises in ensuring the reaction has initiated before excessive accumulation of organic halide occurs or that the reaction does not stall and then reinitiate. Specifically, in production-scale equipment, it is sometimes difficult to ascertain whether initiation has occurred at all and whether it is safe to proceed. By using in situ infrared technology (FTIR), we have developed a method for safer scale-up of Grignard chemistry that can definitively identify that initiation has occurred. The process would involve adding approximately 5% of the organic halide charge and waiting for the initiation to occur using an in situ FTIR probe. FTIR spectroscopy can be used to monitor the accumulation of the halide and reveal when initiation occurs by the resulting decrease in the infrared absorbance. Once it has been determined that the organic halide has reacted as a result of the initiation, it is safe to proceed with the remaining halide charge. The organic halide concentration can then be continuously monitored after initiation to ensure the reaction does not stall or to halt the feed if it does stall. Further, it was shown that IR can be used to quantify the amount of water that is present in THF which is needed to confirm that the THF is dry. The IR results along with reaction calorimetry and ventsizing data are discussed.
- Ende, David J.,Clifford, Pamela J.,Deantonis, David M.,Santamaria, Charles,Brenek, Steven J.
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p. 319 - 329
(2013/09/08)
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- 1,1,2-TRIPHENYLBUT-1-ENE DERIVATIVES
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Novel (E)-1-[4'-(2-alkylaminoethoxy)phenyl]-1-(3'-hydroxyphenyl)-2-phenylbut-1-enes of the general formula STR1 wherein R 1 and R. sup.2 may be the same or different, provided that, when R 1 and R 2 are the same, each of them is a methyl or ethyl radical, and when R 1 and R 2 are different, one of them is hydrogen and the other is a methyl or ethyl radical, and the therapeutically compatible salts thereof, have a marked anti-estrogenic effect and are suitable for treating hormone-dependent mammary tumors.The compounds can be prepared by dehydrating carbinols of the general formula STR2 wherein R 1 and R 2 may be the same or different, provided that, when R. sup.1 and R 2 are the same, each of them is a methyl or ethyl radical, and when R 1 and R 2 are different, one of them is a benzyl radical and the other is a methyl or ethyl radical; and wherein R 3 is hydrogen or an easily hydrolyzable protecting group, through the action of mineral acid while removing any protecting group present, isolating through crystallization the E-form from the pair of isomers obtained, and removing by hydrogenolysis any benzyl group present.Compositions comprising the subject 1,1,2-triphenylbut-1-ene derivatives are described also. The corresponding novel 1,1,2-triphenylbut-1-ene derivatives having the (Z) configuration are also disclosed.
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- Hydroxy derivatives of tamoxifen
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In the exploration of the structural features that affect the RBA (binding affinity for the estrogen receptor of rat uterus relative to that of estradiol) in the tamoxifen [trans-(Z)-1-[4-(dimethylamino)ethoxy]-1,2-diphenyl-1-butene] series, several derivatives variously substituted in the 1-phenyl group have been synthesized. In the tamoxifen series, the descriptors E and Z, which define the configuration of the geometrical isomers and depend on the location and nature of substituents in the aromatic moieties and the ethyl group, may vary, although the relative configuration (cis or trans) does not. In order to avoid confusion the terms cis and trans will be used in this paper to refer to the relative positions of the 4-[2-(dimethylamino)ethoxy]phenyl and ethyl (or hydroxyethyl, hydroxypropyl, or bromo) substituents attached to the ethene moiety]. The final stage of each synthesis involved acid-catalyzed dehydration of a tertiary alcohol, and, in contrast to the known 3- and 4-hydroxy derivatives which were obtained as near-equimolar cis,trans mixtures, only the trans forms of the 2-hydroxy, 2-methyl, 2,4-dihydroxy, and 4-hydroxy-2-methyl derivatives were obtained. Also, in contrast to the trans forms of the 3- and 4-hydroxy derivatives, which are readily equilibrated to cis,trans mixtures, the trans 2-hydroxy derivative could not be isomerized. Tamoxifen and 2-methyltamoxifen had similar RBA's (~1% of that of E2), but that of 2-hydroxytamoxifen was much lower (0.1%). Introduction of a second hydroxyl group (2,4-dihydroxy derivative) enhanced the RBA, and for the 4-hydroxy-2-methyl derivative, the RBA and growth inhibitory activity against the MCF-7 mammary tumor cell line in vitro were high and comparable to those of 4-hydroxytamoxifen, a metabolite of the parent drug. Tamoxifen derivatives hydroxylated at positions 3 or 4 of the 1-butene moiety and the 5-hydroxy-1-pentene analogue were also synthesized, but they had very low RBA values.
- Foster,Jarman,Leung,McCague,Leclercq,Devleeschouwer
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p. 1491 - 1497
(2007/10/02)
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- Estrogenic and Antiestrogenic Activity of Monophenolic Analogues of Tamoxifen, (Z)-2--N,N-dimethylethylamine
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Five hydroxylated analogues of tamoxifen -N,N-dimethylethylamine> and its geometric isomer were prepared by reaction of protected hydroxy-α-ethyldeoxybenzoins with 4-phenylmagnesium bromide, followed by acid-catalyzed dehydration-deprotection and chromatographic separation of isomer mixtures.Estrogen receptor binding affinity and estrogenic and antiestrogenic activity of each of the compounds were determined in the rat, in comparison with 4-hydroxytamoxifen (2).The new compounds had a wide rangeof receptor binding affinities, with that of 3-hydroxytamoxifen (6c), the most strongly bound, approaching that of estradiol.The trans isomers 6a,b were more strongly bound than were the cis isomers 7a,b.Antiestrogenic activity was seen in all compounds except 7b.This was also true for estrogenic activity, except that in 6c this activity was also substantially reduced.Maximal antiestrogenic effectiveness of 6c occurred at a 10-fold greater daily dose (50 μg/rat) than that required for maximal effect of 2.
- Ruenitz, Peter C.,Bagley, Jerome R.,Mokler, Corwin M.
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p. 1056 - 1060
(2007/10/02)
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