- PROCESSES FOR THE PREPARATION OF THALIDOMIDE
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The present invention provides a process for the preparation of thalidomide (I) comprising: i) reacting a compound of formula (II), where one of R represents -OH or -NH2 and the other of R represents -NH2 or -OH, respectively, with a phthaloylating agent in the presence of a base and a a non-polar organic solvent to obtain a phthaloyl derivative where R have the same meanings as above; and ii) dehydrating the phthaloyl derivative using a dehydrating agent selected from an acid anhydride, an acid halide, an ion exchange resin or a molecular sleve to obtain thalidomide (I).
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Page/Page column 15
(2009/08/14)
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- Thiothalidomides: Novel Isosteric Analogues of Thalidomide with Enhanced TNF-α Inhibitory Activity
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Thalidomide is being increasingly used in the clinical management of a wide spectrum of immunologically-mediated and infectious diseases, and cancers. However, the mechanisms underlying its pharmacological action are still under investigation. In this regard, oral thalidomide is clinically valuable in the treatment of erythema nodosum leprosum (ENL) and mutiple myeloma and effectively reduces tumor necrosis factor-α (TNF-α) levels and angiogenesis in vivo. This contrasts with its relatively weak effects on TNF-α and angiogenesis in in vitro studies and implies that active metabolites contribute to its in vivo pharmacologic action and that specific analogues would be endowed with potent activity. Our focus in the structural modification of thalidomide is toward the discovery of novel isosteric active analogues. In this regard, a series of thiothalidomides and analogues were synthesized and evaluated for their TNF-α inhibitory activity against lipopolysacharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC), This was combined with a PBMC viability assay to differentiate reductions in TNF-α secretion from cellular toxicity. Two isosteric analogues of thalidomide, compounds 15 and 16, that mostly reflect the parent compound, together with the simple structure, dithioglutarimide 19, potently inhibited TNF-α secretion, compared to thalidomide, 1. The mechanism underpinning this most likely is posttranscriptional, as each of these compounds decreased TNF-α mRNA stability via its 3′-UTR. The potency of 19 warrants further study and suggests that replacement of the amide carbonyl with a thiocarbonyl may be beneficial for increased TNF-α inhibitory action. In addition, an intact phthalimido moiety appeared to be requisite for TNF-α inhibitory activity.
- Zhu, Xiaoxiang,Giordano, Tony,Yu, Qian-Sheng,Holloway, Harold W.,Perry, Tracy Ann,Lahiri, Debomoy K.,Brossi, Arnold,Greig, Nigel H.
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p. 5222 - 5229
(2007/10/03)
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- Chiral inversion and hydrolysis of thalidomide: Mechanisms and catalysis by bases and serum albumin, and chiral stability of teratogenic metabolites
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The chiral inversion and hydrolysis of thalidomide and the catalysis by bases and human serum albumin were investigated by using a stereoselective HPLC assay. Chiral inversion was catalyzed by albumin, hydroxyl ions, phosphate, and amino acids. Basic amino acids (Arg and Lys) had a superior potency in cataLyzing chiral inversion compared to acid and neutral ones. The chiral inversion of thalidomide is thus subject to Specific and general base catalysis, and it is suggested that the ability of HSA to catalyze the reaction is due to the basic groups of the amino acids Arg and Lys and not to a single catalytic site on the macromolecule. The hydrolysis of thalidomide was also base-catalyzed. However, albumin had no effect on hydrolysis, and there was no difference between the catalytic potencies of acidic, neutral, and basic amino acids. This may be explained by different reaction mechanisms of the chiral inversion and hydrolysis of thalidomide. Chiral inversion is deduced to occur by electrophilic substitution involving specific and general base catalysis, whereas hydrolysis is thought to occur by nucleophilic substitution involving specific and general base as well as nucleophilic catalysis. As nucleophilic attack is sensitive to steric properties of the catalyst, steric hindrance might be the reason albumin is not able to catalyze hydrolysis. 1H NMR experiments revealed that the three teratogenic metabolites of thalidomide, in sharp contrast to the drug itself, had complete chiral stability. This leads to the speculation that, were some enantioselectivity to exist in the teratogenicity of thalidomide, it could result from fast hydrolysis to chirally stable teratogenic metabolites.
- Reist, Marianne,Carrupt, Pierre-Alain,Francotte, Eric,Testa, Bernard
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p. 1521 - 1528
(2007/10/03)
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- A Convenient Asymmetric Synthesis of Thalidomide
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Benzyloxyamine reacted with BOC-glutamic-α-phenyl ester in the presence of carbodiimide to give BOC-amino-N-benzyloxypiperidinedione.Deprotection of the amino group followed by phthaloylation led to N-benzyloxythalidomide which was then converted into thalidomide.
- Robin, Sylvie,Zhu, Jiarong,Galons, Herve,Pham-Huy, Chuong,Claude, Jean Roger,et al.
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p. 1249 - 1252
(2007/10/02)
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