Indoles pharmaceuticals

This brief survey of indole pharmaceuticals and indole candidate drugs is necessarily incomplete. Many more indoles are known that have excellent biological activity, but space does not permit coverage. For example, myriad indole alkaloids have a range of biological activities, and some, like the antihypertensive reserpine, are clinically useful. In addition, the many indohne- and oxindole-based pharmaceuticals could not be included in this chapter. 

The indole ring is incorporated into the stmcture of the amino acid tryptophan [6912-86-3] (6) and occurs in proteins and in a wide variety of plant and animal metaboUtes. Much of the interest in the chemistry of indole is the result of efforts to understand the biological activity of indole derivatives in order to develop pharmaceutical appHcations. 

Synthetic Derivatives of Indoles as Pharmaceuticals. Thousands of indole derivatives have been prepared and evaluated as potential pharmaceuticals (32). Of those which have been put into use perhaps the most important are the nonsteroidal antiinflammatory agent indomethacin [53-86-1] (10) (33) and the p-adrenergic blocker pindolol [13823-86-9] (11) (34). 

Many patents have been issued on the use of pyrogaUol derivatives as pharmaceuticals. PyrogaUol has been used extemaUy in the form of an ointment or a solution in the treatment of skin diseases, eg, psoriasis, ringworm, and lupus erythematosus. GaUamine triethiodide (16) is an important muscle relaxant in surgery it also is used in convulsive-shock therapy. Trimethoprim (2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine) is an antimicrobial and is a component of Bactrin and Septra. Trimetazidine (l(2,3,4-trimethoxybenzyl)piperazine (Vastarel, Yosimilon) is used as a coronary vasodilator. l,2,3,4-Tetrahydro-6-methoxy-l-(3,4,5-trimethoxyphenyl)-9JT-pyrido[3,4- ]indole hydrochloride is useful as a tranquilizer (52) (see Hypnotics, sedatives, ANTICONVULSANTS, AND ANXIOLYTICS). Substituted indanones made from pyrogaUol trimethyl ether depress the central nervous system (CNS) (53). Tyrosine-and glycine(2,3,4-trihydroxybenzyl)hydrazides are characterized by antidepressant and anti-Parkinson activity (54). 

In the frame of a medicinal project at J J Pharmaceutical Research and Development aimed at designing new potent and selective glycogen synthase kinase-3/i (GSK-3/3) inhibitors, the C-3 derivatization of the 1-methyl-4-[l-alkyl-lff-indol-3-yl]-lff-pyrrole-2,5-dione scaffold was explored [31]. Microwave-assisted Stille reaction of 3-chloro-l-methyl-4-[l-alkyl-lff-indol-3-yl]-lH-pyrrole-2,5-diones with (2,4-dimethoxy-5-pyrimidinyl)(tributyl) stannane at 200 °C yielded in 6 min the desired 3,4-diaryl-lff-pyrrole-2,5-diones in moderate yields (Scheme 12). 

Researchers from Eli Lilly pharmaceuticals, (a company founded in 1876 by Colonel Eli Lilly veteran of the US Civil War), undertook further intensive phytochemical studies and characterized 60 alkaloids, of which a group of 20 binary indole alkaloids—including vincristine and vinblastine. Vinblastine sulphate (Velbe ) inhibits the polymerization of tubulin and is used to treat generalized Hodgkin s disease and chorionepithelioma, whereas vincristine sulphate (Oncovin ) is used to treat leukemia in children. 

The occurrence of the indole subunit is well established within the class of natural products and pharmaceutically active compounds. Recently, the Reissig group developed an impressive procedure for the assembly of highly functionalized in-dolizidine derivatives, highlighting again the versatility of domino reactions [8]. The approach is based on a samarium(II) iodide-mediated radical cydization terminated by a subsequent alkylation which can be carried out in an intermolecular - as well as in an intramolecular - fashion. Reaction of ketone 3-11 with samarium(ll) iodide induced a 6-exo-trig cydization, furnishing a samarium enolate intermediate... 

David Wilkins obtained his Ph.D. in 1986 working with Professor A. H. Jackson and Dr. P. V. R. Shannon at University College Cardiff, Wales, working on the synthesis of the Aspidosperma indole alkaloids. He then did two years of postdoctoral studies with Professor P. M. Cullis at the University of Leicester, UK, working on the mechanism of thiophosphoryl-transfer reactions. In 1989, he joined the medicinal chemistry department at what was then Boots Pharmaceuticals in Nottingham (UK) and which became part of BASF Pharma in 1995. In 2001, he joined Key Organics Ltd., where he is currently employed as a principal chemist in the Contract Synthesis Department. 

With this tandem hydroformylation/hydrazone formation/Fischer indolization 3-substituted indoles such as valuable intermediates for the synthesis of pharmaceuticals as well as pharmaceuticals can be obtained in a very... 

Aryl indole as a G-protein-coupled receptor (GPCR) privileged scaffold. The indole ring is a premier example of a privileged scaffold. The heterocycle is present in a profusion of medicinally important natural products and pharmaceutical substances, and it is associated with an extraordinary manifold of biological... 

EXTENSIONS AND COMMENTARY In the 1960 s there was quite a bit of interest in a couple of pharmaceutical houses with the indole analogues of amphetamine. Both the alpha-methylated tryptamine (this compound, a-MT) and the alpha-ethylated homologue (a-ET, see its separate recipe) were found to be effective monoamine oxidase inhibitors, and both were clinically studied as potential antidepressants. The ethyl compound became a commercial drug, offered by the Upjohn Company as Monase, but now is considered to be without medical use and is a Schedule I drug. It is interesting that this methyl compound, a-MT was also a medically available antidepressant in the Soviet Union in the 1960 s and was sold under the name of Indopan, in 5 and 10 milligram tablets. 

Benzofuran is prepared in semicommercial amounts. Its manufacture from o-nitroethylbenzene (as well as that of indole and benzo[fc]thio-phene) has been considered.104 Alkylbenzofurans are prepared in the pharmaceutical industry as basic products.105... 

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