- Effect of molecular structure on thermoresponsive behaviors of pyrrolidone-based water-soluble polymers
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This paper describes the molecular structure dependent thermoresponsive behaviors of pyrrolidone-based water-soluble polymers. A series of well-defined poly[N-(2-methacryloyloxyethyl)pyrrolidone] (PNMEP), poly[N-(3- acryloyloxypropyl)pyrrolidone] (PNAPP), and poly[N-(3-methacryloyloxypropyl) pyrrolidone] (PNMPP) were synthesized via visible light activating RAFT polymerization at 25 °C. Kinetic studies indicate a rapid and well-controlled behavior of this polymerization. Gel permeation chromatography (GPC) and 1H NMR analysis confirm their intact molecular structure, well-defined molecular weight, and narrow distribution. Laser light scattering and temperature-variable 1H NMR analyses demonstrate that the cloud point of a PNMEP sample at a degree of polymerization (DP) of 96 is 1.5 °C lower than that of PNAPP at a DP = 104. Additional backbone methyl groups in PNMPP lead to a dramatic cloud point lowering, e.g., cloud point of PNMPP at a DP = 100 is 37 °C lower than that of PNAPP at a DP = 104. This is contrary to what was observed in poly(N-isopropylacrylamide) (PNIPA) and its polymethacrylamide analogues. These pyrrolidone-based polymers show a dramatic solvent isotopic effect that is different from that of PNIPA; e.g., the cloud point of PNMEP at a DP = 237 is 8.5 °C lower in D2O than in H2O. Increasing polymer chain length or hydrophobicity may suppress this solvent isotopic effect. This phase transition is correlated to Hofmeister series but more sensitive than PNIPA. Na2CO3 dramatically lowers cloud point, while NaI significantly improves cloud point, up to full dissolution in H2O at 95 °C. The solvent isotopic effect in NaCl or Na2CO3 solution is the same as what observed in solution absent of salt. Upon heating D2O solution of PNMEP, the polymer first forms the hydrated irregular colloidal aggregates near the cloud point, the phase transition occurs at the fully hydrated state at cloud point, and further heating leads to the dehydration and separation from D2O. However, in NaCl solution, the dehydration of PNMEP occurs subsequently from apolar backbones, spacers, and finally pyrrolidone groups.
- Sun, Jun,Peng, Yifeng,Chen, Ying,Liu, Yu,Deng, Junjie,Lu, Lican,Cai, Yuanli
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- New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates
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The syntheses of the naturally occurring indolizidine alkaloid (±)-tashiromine and its unnatural epimer (±)-epitashiromine are demonstrated through the use of enaminone chemistry. The impact of various electron-withdrawing substituents at the C-8 position of the indolizidine core on the preparation of the bicyclic system is described.
- Riley, Darren L.,Michael, Joseph P.,De Koning, Charles B.
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supporting information
p. 2609 - 2613
(2017/01/09)
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- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
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The present invention has its object to provide a 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented with the Formula (1) , or the pharmaceutically acceptable salt, which is effective as a therapeutic and prophylactic agent for diabetes, diabetic nephropathy, or glomerulosclerosis.
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- Pilsicainide and its oxymethylene analog: Facile alternative syntheses and in vitro testing on human skeletal muscle sodium channels
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Facile, alternative synthetic routes gave access to both pilsicainide [N-(2,6-dimethylphenyl)-2-tetrahydro-lH-pyrrolizin-7a(5H)-ylacetamide, 1], a well-known Ic antiarrhythmic drug, and its oxymethylene analog 2. Both compounds were tested on human skeletal muscle voltage-gated sodium channels, hNavl.4, transfected in tsA201 cells. 7a-[2-(2,6-Dimethylphenoxy)ethyl]hexahydro-lH-pyrrolizine (2) behaved as a bioisostere of 1, exerting a 4-fold more potent use-dependent block.
- Bruno, Claudio,Catalano, Alessia,Desaphy, Jean-Francois,Cavalluzzi, Maria M.,Carocci, Alessia,Dipalma, Antonella,Franchini, Carlo,Lentini, Giovanni,Camerino, Diana Conte,Tortorella, Vincenzo
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p. 2011 - 2026
(2008/09/18)
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- Quinazoline derivatives and pharmaceutical compositions containing them
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The invention relates to quinazoline derivatives of formula (1) wherein m is an integer from 1 to 2; R1represents hydrogen, hydroxy, halogeno, nitro, trifluoromethyl, cyano, C1-3alkyl, C1-3alkoxy, C1-3alkylthio, or —NR5R6(wherein R5and R6, which may be the same or different, each represents hydrogen or C1-3alkyl); R2represents hydrogen, hydroxy, halogeno, methoxy, amino or nitro; R3represents hydroxy, halogeno, C1-3alkyl, C1-3alkoxy, C1-3alkanoyloxy, trifluoromethyl, cyano, amino or nitro; X1represents —O—, —CH2—, —S—, —SO—, —SO2—, —NR7CO—, —CONR8—, —SO2NR9—, —NR10SO2— or —NR11— (wherein R7, R8, R9, R10and R11each independently represents hydrogen, C1-3alkyl or C1-3alkoxyC2-3alkyl); R4represents an optionally substituted 5 or 6 membered saturated carbocyclic or heterocyclic group or a group which is alkenyl, alkynyl or optionally substituted alkyl, which alkyl group may contain a heteroatom linking group, which alkenyl, alkynyl or alkyl group may carry a terminal optionally substituted group selected from alkyl and a 5 or 6 membered saturated carbocyclic or heterocyclic group, and salts thereof; processes for their preparation, pharmaceutical compositions containing a compound of formula (I) or a pharmaceutically acceptable salt thereof as active ingredient. The compounds of formula (I) and pharmaceutically acceptable salts thereof inhibit the effects of VEGF, a property of value in the treatment of a number of disease states including cancer and rheumatoid arthritis.
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- A hydroformylation route to diazabicycloalkanes and oxazabicycloalkanes containing medium and large rings
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Diazabicycloalkanes and oxazabicycloalkanes containing medium and large rings can be prepared by rhodium-catalysed reactions of N-alkenylpropane-1,3-diamines and 2-(alkenylamino)ethanols with H2/CO in excellent yields without the need for high dilution. Selective ring opening of these compounds can lead to large heterocycles. CSIRO 1999.
- Bergmann, David J.
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p. 1131 - 1138
(2007/10/03)
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- Formal synthesis of two Elaeocarpus alkaloids: elaeocarpine and isoelaeocarpine
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1-(3-Acetoxypropyl)pyrrolidine-2-thione 7, prepared by acetylation and thionation of the readily accessible 1-(3-hydroxypropyl)pyrrolidin-2-one 5, undergoes Eschenmoser alkylidenation (sulfide contraction) with two phenacyl bromides to give the vinylogous amides (E)-1-(3-acetoxypropyl)-2-benzoylmethylenepyrrolidine 8 and the corresponding 2-methoxy-6-methylbenzoyl analogue 14.Reduction of the latter with lithium aluminium hydride yields 1-(3-hydroxypropyl)-2-(2-methoxy-6-methylbenzoyl)methylpyrrolidine 12, thereby completing a formal synthesis of the Elaeocarpus alkaloids elaeocarpine 10 and isoelaeocarpine 11.
- Michael, Joseph P.,Parsons, Andrew S.
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- A NEW SYNTHESIS OF BICYCLO-OXAZINE DERIVATIVES
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There has been described a new synthesis of bicyclo-tetrahydro--oxazine derivatives from five- and six-membered lactams by anodic oxidation, followed by simultaneous cyclization.
- Okita, Makoto,Wakamatsu, Takeshi,Mori, Miwako,Ban, Yoshio
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p. 1089 - 1092
(2007/10/02)
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