Inhibition of adenosine A2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A2AR (Ki=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours). 相似文献
The reaction of 2‐amino‐3‐carbomethoxythiophene ( 1a ) and 2‐amino‐3‐carboethoxy‐4,5‐dimethylthiophene ( 1b ) with methyl‐ or ethylmagnesium chloride leads to new 3‐(1‐aminoalkylidene)‐3H‐thiophen‐2‐ones 4a—d in good yields (60—87%). Treatment of the compounds 4a and 4c with catalytic amounts of p‐TsOH in boiling CHCl3 afforded the (±)‐4,4′‐bis‐(1‐aminoalkylidene)‐3′,4′‐4H,2′H‐[2,3′]bithiophenyl‐5,5′‐diones 9a and 9b as new interesting heterocycles in preparatively useful yields (60/mdash;65%). 相似文献
PPARγ agonist DIM‐Ph‐4‐CF 3 , a template for RXRα agonist (E)‐3‐[5‐di(1‐methyl‐1H‐indol‐3‐yl)methyl‐2‐thienyl] acrylic acid: DIM‐Ph‐CF3 is reported to inhibit cancer growth independent of PPARγ and to interact with NR4A1. As both receptors dimerize with RXR, and natural PPARγ ligands activate RXR, DIM‐Ph‐4‐CF3 was investigated as an RXR ligand. It displaces 9‐cis‐retinoic acid from RXRα but does not activate RXRα. Structure‐based direct design led to an RXRα agonist.
The properties of segmented‐copolymer‐based H‐bonding and non‐H‐bonding crystallisable segments and poly(tetramethylene oxide) segments were studied. The crystallisable segments were monodisperse in length and the non‐hydrogen‐bonding segments were made of tetraamidepiperazineterephthalamide (TPTPT). The polymers were characterised by DSC, FT‐IR, SAXS and DMTA. The mechanical properties were studied by tensile, compression set and tensile set measurements. The TPTPT segmented copolymers displayed low glass transition temperatures (Tg, ?70 °C), good low‐temperature properties, moderate moduli (G′ ≈ 10–33 MPa) and high melting temperatures (185–220 °C). However, as compared to H‐bonded segments, both the modulus and the yield stress were relatively low.
Triterpenes of betulinic acid type exhibit many interesting biological activities. Therefore a series of new 3α‐hydroxy‐lup‐20(29)‐ene‐23,28‐dioic acid derivatives 2a—22 with putative pharmacological activities were synthesized. As starting compounds 3α‐hydroxy‐lup‐20(29)‐ene‐23,28‐dioic acid ( 1a ), isolated from Schefflera octophylla, or its 3‐O‐acetyl derivative 1b were used. Mono‐ and diesters ( 2a—b from 1a , and 4d from 4c ) were prepared with CH2N2. Oxidation of the isopropenyl side chain with OsO4 yielded the 20,29‐diols ( 4a—b from 1b , and 19 from 17 ), which were in the case of 4b further transformed to the 29‐norketones 8a/mdash;b . Oxidation of the isopropenyl side chain with m‐chloroperbenzoic acid afforded the 20,29‐epoxide 12 (from 1b ) and the 29‐aldehydes and a‐hydroxy aldehydes ( 13a—c from 2a, 14a—c from 2b , and 16a—c from 15a ). Ring A was modified by a tosylation—elimination sequence using p‐TsCl/NaOAc, which afforded diolefin 15a (from 2a ) with Δ2,20(29) double bonds or 23‐nor‐Δ3,20(29)diolefin 17 (from 1a ). Compounds 4b, 4c , and 8a were coupled with L ‐methionin, L ‐phenylalanin, L ‐alanin, L ‐serin, and L ‐glutaminic acid via amide bonds at positions 23 and 28 to afford the amino acid conjugates 5a—7b and 9a—11 . 相似文献
A more practical and efficient catalytic asymmetric chlorolactonization of styrene‐type carboxylic acids with 1,3‐dichloro‐5,5‐dimethylhydantoin (DCDMH) using C3‐symmetric cinchonine‐squaramide (CSCS) as organocatalyst has been developed. A series of chiral chloro‐substituted isochroman‐1‐ones was obtained in excellent yields (up to 95%) and enantioselectivities (up to 99% ee), whwereby the results for chloro‐substituted isochroman‐1‐ones are the best ever achieved. The catalyst can be recovered and reused for six cycles. Moreover, the chlorolactonization product 3b was further transformed to optically active bicyclic isochroman‐1‐one derivatives in high yield without losing the enantioselectivity. Furthermore, compounds 3e and 2n proved to be highly potent inhibitors of the HIV‐1 in TZM‐bl cells.
In the presence of Na2CO3 (1S,3S)‐ and (1R,3S)‐1‐(2,2‐dimethoxyethyl)‐2‐(1,3‐dioxobutyl)‐3‐(1,3‐dioxo‐butyl)oxymethyl‐1,2,3,4‐tetrahydrocarboline ( 1 ) were transformed into (1S,3S)‐ and (1R,3S)‐1‐(2,2‐dimethoxyethyl)‐2‐(1,3‐dioxobutyl)‐3‐hydroxymethyl‐1,2,3,4‐tetrahydrocarboline ( 2 ), which were cyclized to (6S)‐3‐acetyl‐6‐hydroxymethyl‐4,6,7,12‐tetrahydro‐4‐oxoindolo[2,3‐a]quinolizine ( 4 ), via(6S,12bS)‐ and (6S,12bR)‐3‐acetyl‐2‐hydroxyl‐6‐hydroxymethyl‐1,2,3,4,6,7,12,12b‐octahydro‐4‐oxoindolo[2,3‐a]quinoline ( 3 ). (6S)‐ 4 was coupled with Boc‐Gly, Boc‐L‐Asp(β‐benzyl ester), or Boc‐L‐Gln to give 6‐amino acid substituted (6S)‐3‐acetyl‐4,6,7,12‐tetrahydro‐4‐oxoindolo[2,3‐a]quinolizines 5a , 5b , or 5c , respectively. After the removal of Boc from (6S)‐ 5a (6S)‐3‐acetyl‐6‐glycyl‐4,6,7,12‐tetrahydro‐4‐oxoindolo[2,3‐a]quinolizine ( 6 ) was obtained. The anticancer activities of (6S)‐ 5 and (6S)‐ 6 in vitro were tested. 相似文献
A synthetic strategy has been developed for the synthesis of 2‐dialkylaminoquinolines from easily available quinoline N‐oxides, tertiary amines, diisopropyl H‐phosphonate and carbon tetrachloride (CCl4) in one pot under metal‐free conditions at room temperature.
Nineteen new halogenated diarylpyridinamine (DAPA) analogues modified at the phenoxy C‐ring were synthesized and evaluated for anti‐HIV activity and certain drug‐like properties. Ten compounds showed high anti‐HIV activity (EC50<10 nM ). In particular, (E)‐6‐(2′′‐bromo‐4′′‐cyanovinyl‐6′′‐methoxy)phenoxy‐N2‐(4′‐cyanophenyl)pyridin‐2,3‐diamine ( 8 c ) displayed low‐nanomolar antiviral potency (3–7 nM ) against wild‐type and drug‐resistant viral strains bearing the E138K or K101E mutations, which are associated with resistance to rilvipirine ( 1 b ). Compound 8 c exhibited much lower resistance fold changes (RFC: 1.1–2.1) than 1 b (RFC: 11.8–13.0). Compound 8 c also exhibited better metabolic stability (in vitro half‐life) than 1 b in human liver microsomes, possessed low lipophilicity (clog D: 3.29; measured log P: 3.31), and had desirable lipophilic efficiency indices (LE>0.3, LLE>5, LELP<10). With balanced potency and drug‐like properties, 8 c merits further development as an anti‐HIV drug candidate. 相似文献
The present report describes an efficient and clean generation of sulfenate salts (R1SO−) by pyrolysis of readily available tert‐butyl sulfoxides to give sulfenic acids (R1SOH) and traceless isobutene, followed by hydrogen abstraction with a weak inorganic base (K3PO4). The relevance of this process was exemplified through an in situ palladium‐catalyzed cross‐coupling reaction with aryl halides/triflates leading to aryl sulfoxides. The operationally simple C S bond‐forming protocol developed uses Pd(dba)2 as catalyst and Xantphos as ligand in toluene or a toluene/H2O mixture. Further extensions include the use of di‐tert‐butyl sulfoxide as an equivalent for sulfur monoxide dianion (SO2−) and the development of diastereoselective versions in the [2.2]paracyclophane and biaryl series.
A nickel‐catalyzed regio‐ and stereoselective reductive coupling of oxa‐ and azabicyclic alkenes with activated alkenes and electron‐rich alkynes is described. Thus, 7‐oxabenzonorbornadienes underwent reductive coupling with various vinyl ketones such as ethyl, methyl, propyl and α‐methyl‐substituted vinyl ketones, in the presence of a nickel(II) iodide (NiI2), zinc (Zn), and water catalyst system in acetonitrile at 50 °C for 14 h to afford 2‐alkylnaphthalenes in good to excellent yields. Under similar reaction conditions, 7‐azabenzonorbornadiene derivatives provided cis‐2‐alkyl‐1,2‐dihydronaphthalene derivatives in high yields. On the other hand, the nickel(II) iodide, tris(4‐fluorophenyl)phoshine [P(4‐FC6H4)3] and zinc catalyst system successfully catalyzed the reductive coupling reaction of electron‐rich alkynes, with 7‐aza‐ and 7‐oxabenzonorbornadienes to give cis‐2‐alkenyl‐1,2‐dihydronaphthalene derivatives in good to excellent yields. In the reaction, a mild reducing agent (zinc) and simple hydrogen source (water) were used.
Metal triflate‐catalysed intermolecular Friedel–Crafts reactions involving electron‐rich benzenoid arenes and spiroepoxyoxindoles at the spiro‐centre have been developed for the exclusive regioselective synthesis of 3‐aryl‐(3‐hydroxymethyl)oxindoles with an all‐carbon quaternary centre. Selective ring opening of spiroepoxyoxindoles with phenols provided a direct access to 3‐(hydroxymethyl)‐3‐(2‐hydroxyaryl)oxindoles. We have utilized this methodology successfully as the key step for the synthesis of benzofuroindolines and 2H‐spiro[benzofuran]‐3,3′‐oxindoles.
An iron(III)‐catalyzed C‐3 functionalization of flavones has been achieved using tert‐butyl peroxybenzoate (TBPB)/potassium persulphate (K2S2O8) oxidant combinations with a suitable solvent. In the presence of iron(III)/tert‐butyl peroxybenzoate/potassium persulphate, the reaction of flavones in cycloalkanes afforded exclusive C‐3 cycloalkylation via C –C coupling, whereas the solvent N,N‐dialkylformamide provided C‐3 amidation via C –C coupling. Under identical reaction conditions just by switching the solvent to chlorobenzene, C‐3 methylated flavones were obtained where tert‐butyl peroxybenzoate (TBPB) served as the source of the methyl group.
Several metal and nitrogen‐rich salts of the recently presented 5‐(5‐azido‐1H‐1,2,4‐triazol‐3‐yl)tetrazole (AzTT), including silver ( 1 ), copper(I) ( 2 ), potassium ( 3 ), cesium ( 4 ), copper(II) ( 7 ), ammonium ( 8 ), and guanidinium ( 9 ), as well as the respective double‐salts of 3 , 4 , 8 and 9 , were prepared and well characterized by IR and multinuclear (1H, 13C, 14N) NMR spectroscopy, DSC, mass spectrometry, elemental analysis and one ( 4 ) additionally by single‐crystal X‐ray diffraction. The sensitivities towards impact, friction and electrostatic discharge were determined according to BAM standards, revealing most of the metal salts as highly sensitive and the nitrogen‐rich salts as insensitive. The metal salts were further tested for their ability of being primary explosives. 相似文献
We describe a most straightforward synthetic method for preparing neurokinin‐1 (NK1) receptor antagonist derivatives by asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts using dinuclear iridium complexes with enantiopure diphosphine ligands, affording the corresponding chiral piperidines in high cis‐diastereoselectivity (>95:5) and moderately high enantioselectivity (up to 86%). Deprotection treatments afforded the NK‐1 receptor antagonist (+)‐CP‐99,994 (83% ee). In addition, we observed unique additive effects of 10‐camphorsulfonic acid in the asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts.
An efficient system for the direct catalytic intermolecular α‐arylation of acetamide derivatives with aryl bromides and chlorides is presented. The palladium catalyst is supported by Kwong’s indole‐based phosphine ligand and provides monoarylated amides in up to 95% yield. Excellent chemoselectivities (>10:1) in the mono‐ and diarylation with aryl bromides were achieved by careful selection of bases, solvents, and stoichiometry. Under the coupling conditions, the weakly acidic α‐protons of amides (pKa up to 35) were reversibly depotonated by lithium tert‐butoxide (LiO‐t‐Bu), sodium tert‐butoxide (NaO‐t‐Bu) or sodium bis(trimethylsilyl)amide [NaN(SiMe3)2].
Sodium 5‐cyanotetrazolate sesquihydrate ( 1 ) was prepared from sodium azide and two equivalents of sodium cyanide under acidic conditions. Sodium 5‐cyanotetrazolate sesquihydrate ( 1 ) reacts with hydroxylammonium chloride to form 5‐aminohydroximoyl tetrazole ( 2 ). 5‐Aminohydroximoyl tetrazole ( 2 ) is treated with sodium nitrite and hydrochloric acid to form 5‐chlorohydroximoyl‐tetrazole ( 3 ). The chloride azide exchange yields 5‐azidohydroximoyl‐tetrazole monohydrate ( 4 ). When compound 4 is treated with hydrochloric acid, 5‐(1H‐tetrazolyl)‐1‐hydroxytetrazole ( 5 ) is obtained in good yield. Compound 5 can be deprotonated twice by various bases. Different ionic derivatives such as bis(hydroxylammonium) ( 6 ), bis(hydrazinium) ( 7 ), bis(guanidinium) ( 8 ), bis(aminoguanidinium) ( 9 ), bis(ammonium) ( 10 ), and diaminouronium ( 11 ) 5‐(1‐oxidotetrazolyl)‐tetrazolate were synthesized and characterized. With respect to energetic use salts 6 and 7 are most relevant. Compounds 3 – 9 and 11 were characterized using low temperature single‐crystal X‐ray diffraction. All compounds were investigated by NMR and vibrational (IR, Raman) spectroscopy, mass spectrometry and elemental analysis. The thermal properties were determined by differential scanning calorimetry (DSC). The sensitivities towards impact ( 4 : 4 J, 5 : 40 J, 6 : 12 J, 7 : 40 J), friction: ( 4 : 60 N, 5 : 240 N, 6 : 216 N, 7 : 240 N), and electrical discharge ( 5 : 0.40 J, 6 : 0.75 J, 7 : 0.75 J), were investigated using BAM standards and a small scale electrostatic discharge tester. The detonation parameters of 5 – 7 were calculated using the EXPLO5.06 code and calculated (CBS‐4 M) enthalpy of formation values. 相似文献