Showing papers on "Bicyclic molecule published in 1992"

Bis mono-and bicyclic aryl and heteroaryl compounds which inhibit egf and/or pdgf receptor tyrosine kinase

Abstract: This invention relates to bis mono- and/or bicyclic aryl and/or heteroaryl compounds exhibiting protein tyrosine kinase inhibition activity. More specifically, it relates to the method of inhibiting abnormal cell proliferation in a patient suffering from a disorder characterized by such proliferation comprising the administration thereto of an EGF and/or PDGF receptor inhibiting effective amount of said bis mono- and/or bicyclic aryl and/or heteroaryl compound and to the preparation of said compounds and their use in pharmaceutical compositions used in this method.

Bicyclic nucleosides, oligonucleotides, process for their preparation and intermediates

Abstract: Compounds of the formula I in the form of the racemates or enantiomers thereof, ##STR1## in which R 1 and R 2 independently of one another are hydrogen or a protective group, and B is a purine or pyrimidine radical or an analogue thereof, can be used as antiviral active ingredients or for the preparation of biologically active oligonucleotides.

Thermally irreversible photochromic systems. Reversible photocyclization of 1,2-bis (2-methylbenzo[b]thiophen-3-yl)perfluorocyclocoalkene derivatives

Abstract: 1,2-Bis(2-methylbenzo[b]thiophen-3-yl)perfluorocylopentenes undergo thermally irreversible photochromic reactions in which colouration/decolouration cycles can be repeated more than 104 times without significant loss of performance.

A dideazatetrahydrofolate analog lacking a chiral center at C-6: N-[4-[2-(2-amino-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5yl)ethyl[benzoyl]-L-glutamic acid is an inhibitor of thymidylate synthase

Abstract: N-[4-[2-(2-Amino-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5- yl)ethyl]benzoyl]-L-glutamic acid (15), prepared in five steps from 2-pivaloyl-7-deazaguanine, has been found to be an antitumor agent with its primary site of action at thymidylate synthase rather than purine synthesis. This compound appears to be a promising candidate for clinical evaluation.

Pharmacological profile of a series of bicyclic cannabinoid analogs: classification as cannabimimetic agents.

Abstract: Opening of the pyran ring of delta 9-tetrahydrocannabinol (THC) produces cannabidiol, a bicyclic cannabinoid devoid of many pharmacological properties produced by delta 8-THC or delta 9-THC. Interestingly, the bicyclic compound CP-47,497 (VI) has been described as producing many of the pharmacological effects produced by delta 9-THC, and another related bicyclic analog CP-55,940 (XIV) has been used to successfully define a cannabinoid binding site. A series of 16 bicyclic analogs of VI and XIV were evaluated and compared with the pharmacological profile of cannabidiol, delta 8-THC and delta 9-THC. The goals of the studies described herein were to determine whether these bicyclic analogs possess similar pharmacological properties of delta 9-THC, to compare pharmacological activity after s.c. and i.v. administration, and to evaluate the structure-activity relationship of this series of analogs for further insight into cannabinoid mechanism of action. Each analog was evaluated for its ability to produce hypoactivity, hypothermia, antinociception and catalepsy in mice. The ED50 values generated from these assays were averaged to provide an index of activity. The ED50 values for delta 9-THC varied from 1.0 to 1.5 mg/kg, giving an overall index of activity of 1.3. The index for delta 8-THC was 6.0, making this isomer 4-fold less potent. Although several bicyclic analogs (V, VI, VII, VIII, XI, XII, XIV and XVI) proved to be truly cannabimimetic, three (IV, IX and X) were sufficiently unique to be classified as noncannabimimetic. The index of activity of cannabimimetic bicyclic analogs varied from 0.2 to 2.2, although some minor differences between the bicyclics and delta 9-THC exist.(ABSTRACT TRUNCATED AT 250 WORDS)

On the Mechanisms of Enantioselective Reactions Using α,α,α′,α′ -Tetraaryl-1,3-dioxolane-4,5-dimethanol(TADDOL)-Derived Titanates: Differences between C2- and C1-symmetrical TADDOLs – facts, implications and generalizations†

Abstract: The titanates derived from α,α,α′,α′-tetraaryl-1,3-dioxolane-4,5-dimethanols (TADDOLs, prepared from tartrate) act as catalysts for enantioselective additions of dialkylzinc compounds to aldehydes. For the standard reaction chosen for this investigation of the mechanism, the addition of diethylzinc to benzaldehyde, there is very little change of selectivity with different aryl substituents on the TADDOLate ligands (Tables 2–4, examples). With 0.02 to 0.2 equiv. of the chiral titanates, selectivities above 90% are observed only in the presence of excess tetraisopropyl titanate! According to NMR measurements (Fig. 2), the chiral bicyclic titanate and the achiral titanate do not react to give new species under these conditions. From experiments with different stoichiometries of the components, and with different achiral or chiral OR groups on the Ti-atom of the seven-membered ring titanate, it is concluded (i) that a single chiral titanate is involved in the product-forming step, (ii) that the bulky TADDOLate ligand renders the Ti-center catalytically more active than that of (i-PrO)4Ti, due to fast dynamics of ligand exchange on the sterically hindered Ti-center (Table 5, Fig. 3), and (iii) that the role of excess (i-PrO)4Ti is to remove – by ligand exchange – the product alkoxides (R*O) from the catalytically active Ti-center (Scheme 4, Table 6). Three new crystal structures of TADDOL derivatives (two clathrates with secondary amines, and a dimethyl ether) have been determined by X-ray diffraction (Figs. 5–7), and are compared with those previously reported. The distances between the C(aryl)2O oxygen atoms in the C2- and C1-symmetrical structures vary from 2.58 to 2.94 A, depending upon the conformation of their dioxolane rings and the presence or absence of an intramolecular H-bond (Fig. 8). A single-crystal X-ray structure of a spiro-titanate, with two TADDOLate ligands on the Ti-atom, is described (Fig. 9); it contains six different seven-membered titanate-ring conformations in the asymmetric unit (Fig. 10), which suggests a highly flexible solution structure. The structures of Ti TADDOLate complexes are compared with those of C2-symmetrical Ru, Rh, and Pd disphosphine chelates (Table 7). A common topological model is presented for all nucleophilic additions to aldehydes involving Ti TADDOLates (Si attack with (R,R)-derivatives, relative topicity unlike; Fig. 11). Possible structures of complexes containing bidentate substrates for Ti TADDOLate-mediated ene reactions and cycloadditions are proposed (Fig. 12). A simple six-membered ring chair-type arrangement of the atoms involved can be used to describe the result of TADDOLate-mediated nucleophilic additions to aldehydes and ketones, with Ti, Zr, Mg, or Al bearing the chiral ligand (Scheme 6). A proposal is also made for the geometry of the intermediate responsible for enantioselective hydrogenation of N-(acetylamino)cinnamate catalyzed by Rh complexes containing C2-symmetrical diphosphines (Fig. 13).

Blocked photochromism of diarylethenes

Abstract: We designed and synthesized chemical-gated molecules by introducing substitutents tha have hydrogen-bonding ability into 1,2-diarylethenes.

Toward a molecular-size tinkertoy construction set. Preparation of terminally functionalized [n]staffanes from [1.1.1]propellane

Abstract: A facile but low-field synthesis of [n]staffanes (the oligomers of [1.1.1]propellane n=1-5) functionalized on one or both ends is described,and their properties are summarized. The substituents are -COOCH 3 ,-n-C 4 H 9 ,-C 6 H 5 ,-Br,-I and -SCOCH 3 , and their conversion to others,such as -COOH, -COCH 3 and -SH,is demonstrated. it is proposed that these rod-shaped molecules will be useful in the development of a molecular-size civil engeneering construction set analogous to children's toy construction sets

The squalestatins, novel inhibitors of squalene synthase produced by a species of Phoma. II. Structure elucidation.

Abstract: Three novel fungal metabolites 1-3 isolated from cultures of a Phoma sp. C2932, are potent and selective inhibitors of squalene synthase. Their structures have been determined by a combination of spectroscopic, X-ray crystallographic and chemical methods; these natural products incorporate the highly functionalised bicyclic core, [1S-(1 alpha, 3 alpha, 4 beta, 5 alpha, 6 alpha, 7 beta]-4,6,7-trihydroxy- 2,8-dioxabicyclo-[3.2.1]octane-3,4,5-tricarboxylic acid.

A simple asymmetric synthesis of 2-substituted pyrrolidines and 5-substituted pyrrolidinones

Abstract: An efficient procedure for the preparation of the title compounds in high enantiomeric purity has been realized starting from 3-acylpropionic acids. Stereoselective reduction of chiral bicyclic lactams 2a-h, prepared from the corresponding γ-keto acid and (R)-phenylglycinol, using alane or triethylsilane with titanium tetrachloride provided the N-substituted pyrrolidines and pyrrolidinones, respectively. Subsequent cleavage of the phenylglycinol returned the desired amines and lactams. The enantiomeric purity of these compounds was determined to be >98% by chiral stationary-phase HPLC

Single-component organic conductors based on neutral radicals containing the pyrazino-TCNQ skeleton

Abstract: Pyrazino-TCNQ (1a) prepared from 5, 8-diiodoquinoxaline (4a) is, like TCNQ itself, a strong electron acceptor and gives a stable anion radical salt as well as highly conductive charge-transfer crystals with donors. Substituted derivatives 1b-i were similarly prepared from 3,6-diiodo- 1,2-phenylenediamine (5) as a common intermediate, and bulky substituents such as the phenyl or pyridyl groups have very little effect on either the redox properties or planar geometry of 1a. Neutral radicals 3d-g derived from pyridyl-substituted derivatives 1d-g, respectively, are open-shell donor-[pi]-acceptor systems with high electrical amphotericity designed as a new motif for single-component organic conductors. The powder conductivity of 3f was as high as 3.2 [times] 10[sup [minus]5] S cm[sup [minus]1]. 29 refs., 4 figs., 2 tabs.

Pyrazole-related nucleosides. Synthesis and antiviral/antitumor activity of some substituted pyrazole and pyrazolo[4,3-d]-1,2,3-triazin-4-one nucleosides

Abstract: Several pyrazole and pyrazolo[4,3-d]-1,2,3-triazin-4-one ribonucleosides were prepared and tested for antiviral/antitumor activities. Appropriate heterocyclic bases were prepared by standard methodologies. Glycosylation of pyrazoles 6a-e,g,i and of pyrazolo[4,3-d]-1,2,3-triazin-4-ones 12f-1 mediated by silylation with hexamethyldisilazane, with 1-beta-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose, gave in good yields the corresponding glycosides 7a-e,g, 8g,i, 13f,h,k, and 14f, but could not be applied to compounds 12g,i,j,l. To overcome this occurrence, a different strategy involving the preparation, diazotization, and in situ cyclization of opportune pyrazole glycosides 9 and 10 was required. Moreover derivatives having the general formula 5 were considered not only as synthetic intermediates in the synthesis of 3 but also as carbon bioisosteres of ribavirin 4. All compounds were evaluated in vitro for cytostatic and antiviral activity. The pyrazolo[4,3-d]-1,2,3-triazin-4-one nucleosides that resulted were substantially devoid of any activity; only 15h,k showed a moderate cytostatic activity against T-cells. However, pyrazole nucleosides 9b,c,e were potent and selective cytotoxic agents against T-lymphocytes, whereas 9e showed a selective, although not very potent, activity against coxsackie B1.

Controlled molecular aggregation. 1. Cyclic trimerization via hydrogen bonding

Abstract: Vapor pressure osmometric and 1 H NMR dilution studies of quinolone 7, isoquinolone 8, and pyrido[4,3-g]quinolinedione 1, indicate that 1 forms an extremely robust cyclic trimer in solution

Dirhodium tetraacetate catalyzed carbon-hydrogen insertion reaction in N-substituted .alpha.-carbomethoxy-.alpha.-diazoacetanilides and structural analogs. Substituent and conformational effects

Abstract: A series of acyclic α-carbomethoxy-α-diazoacetanilides with different N-substituents, 5a-k, was prepared and the rhodium(II) acetate catalyzed reactions studied. It was found that the rhodium carhenoid reaction with these compounds occurred only at the N-substituent; when the N-substituent is a propargyl group, rhodium carbenoid addition to the triple bond is favored, resulting, ultimately, in the formation of a bicyclic furan derivative 8. With an N-(tert-butyloxycarbonyl)methyl substituent, interception of the rhodium carhenoid by the ester carbonyl oxygen occurred preferentially to give, eventually, 1,4-oxazine derivatives 9 and 9'

5-ht4 receptor antagonists

Abstract: Compounds of formula (I) and pharmaceutically acceptable salts thereof, and the use of a compound of the formula (I): X-CO-CH2-Z, or a pharmaceutically acceptable salt thereof, wherein X is a monocyclic or polycyclic aromatic group, Z is of sub-formula (h), (j) or (k), wherein n1 is 1, 2, 3 or 4; n2 is 0, 1, 2, 3 or 4; n3 is 2, 3, 4 or 5; q is 0, 1, 2 or 3; p is 0, 1 or 2; m is 0, 1 or 2; R5 is hydrogen, C?1-12? alkyl, aralkyl or R5 is (CH2)z-R10 wherein z is 2 or 3 and R10 is selected from cyano, hydroxyl, C1-6 alkoxy, phenoxy, C(O)C1-6 alkyl, COC6H5, -CONR11R12, NR11COR12, SO2NR11R12 or NR11SO2R12 wherein R11 and R12 are hydrogen or C1-6 alkyl; or R5 is straight or branched chain alkylene of chain length 1-6 carbon atoms terminally substituted by aryl, 3 to 8 membered cycloalkyl, 3 to 8 membered heterocyclyl, 5 or 6 membered monocyclic heteroaryl or 9 or 10 membered fused bicyclic heteroaryl linked through carbon, C2-7 alkoxycarbonyl, or secondary or tertiary hydroxy substituted C1-6 alkyl; and R6, R7 and R8 are independently hydrogen or C1-6 alkyl; and R9 is hydrogen or C1-10 alkyl; and their use as pharmaceuticals in the treatment of gastrointestinal disorders, cardiovascular disorders and CNS disorders.

Chemistry of oxaziridines. 18. Synthesis and enantioselective oxidations of the [(8,8-dihalocamphoryl)sulfonyl]oxaziridines

Abstract: The synthesis and enantioselective oxidations of [(8,8-dihalocamphoryl)sulfonyl]oxaziridines [8,8-dichloro-1,7,7-trimethyl-2'-(phenylsulfonyl)spiro[bicyclo[2.2.1]heptane-2,3'-oxinidine]] 13 are reported. These reagents are prepared in two steps from the (camphoxylsulfonyl)imine 4 by treatment of the corresponding azaenolate with electrophilic halogen sources followed by biphasic oxidation of the resulting dihalo imine 6-9 with m-CPBA/K 2 CO 3 . Of these oxaziridines the dichloro reagent 13b, available on a multigram scale, affords the highest enantioselectivities for the asymmetric oxidation of sulfides to sulfoxydes (42-74%) and for the hydroxylation of enolates (often better than 95% ee).

Potential use of carbocyclic nucleosides for the treatment of AIDS: chemo-enzymatic syntheses of the enantiomers of carbovir

Abstract: The lactam (1R),(4S)-2-azabicyclo[2.2.1]hept-5-en-3-one [(–)-2], derived by whole cell enantio-specific hydrolysis of the racemate was converted into (–)-carbovir (–)-1 in ten steps. Lipase catalysed acetylation of 4-cis-hydroxycyclopent-2-enylmethyl triphenylmethyl ether afforded the optically pure ester (+)-3 and the alcohol (–)-9. The former compound was converted into (+)-carbovir (+)-1 in three steps.