Synthesis of 1H‐quinazoline‐2,4‐diones from 2‐aminobenzonitriles by fixation of carbon dioxide with amidine moiety supported polymer at atmospheric pressure

1H‐Quinazoline‐2,4‐diones, which are key intermediates in the synthesis of medicines, were successfully synthesized from 2‐aminobenzonitriles by the fixation of CO₂ in the presence of a polystyrene derivative bearing amidine moiety [poly(amidine)]. A model reaction, that is, the reaction of 2‐aminobenzonitrile ( 1a ) with CO₂ in the presence of N‐methyltetrahydropyrimidine ( MTHP ) revealed that a catalytic amount of MTHP afforded 1H‐quinazoline‐2,4‐dione ( 2a ) quantitatively at atmospheric pressure. Several 1H‐quinazoline‐2,4‐diones ( 2a ‐ 2c ) were successfully synthesized from the corresponding 2‐aminobenzonitriles ( 1a ‐ 1c ) in the presence of poly(amidine). The poly(amidine) could easily be separated from the reaction mixture by filtration and reused in subsequent reactions owing to the heterogeneous system. These demonstrated that poly(amidine) is a useful heterogeneous polymer‐supported reagent for the synthesis of 1H‐quinazoline‐2,4‐diones from CO₂. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 653–657, 2009     

Living cationic ring‐opening polymerization of five‐membered cyclic dithiocarbonate controlled by neighboring group participation of carbamate group

A five‐membered cyclic dithiocarbonate having phenylcarbamate moiety 1 underwent cationic ring‐opening polymerization by using methyl trifluoromethanesulfonate as an initiator in nitrobenzene at 60 °C. Both of the corresponding first‐order kinetic plot and conversion‐molecular weight plot showed linearity to suggest the living fashion of the polymerization, which was then supported by two‐stage polymerization experiment. The living fashion as well as the regioselective formation of the repeating unit suggested significant contribution of the neighboring group participation of the carbamate group to form a stabilized cationic propagating end, of which structure was confirmed by performing an equimolar reaction of 1 and methyl trifluoromethanesulfonate with analyzing the resulting species by NMR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4459–4464, 2007     

Samarium enolate on crosslinked polystyrene beads. III. Anionic initiator for well‐defined synthesis of poly(hydroxyethyl methacrylate) on solid support

A solid‐supported samarium enolate successfully initiated the polymerization of 2‐(trimethylsilyloxy)ethyl methacrylate (TMS‐HEMA) through the living anionic process. In addition, the silyl group was readily removed by treatment of the beads with a weak acid to afford the corresponding well‐defined poly(methacrylate) having a hydroxyethyl group in the side chain (PHEMA). The hydroxyl group of the immobilized PHEMA on the beads was successfully acetylated to give poly(2‐acetoxyethyl methacrylate), which could be quantitatively isolated from the beads by trifluoroacetic acid treatment. Moreover, the hydroxyl group of the immobilized PHEMA could be utilized as an initiator for acid promoted ring opening polymerization of lactone to yield the corresponding graft copolymer. In this method, the residual and excess reagents could be removed by filtration, which demonstrated the applicability of the present technique to a novel method for construction of functional polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4417–4423, 2004     

Mössbauer spectroscopy of the high-pressure phase of pure iron;ɛ-Fe

Hyperfine Interactions - First off-line tests at the ion trap facility SHIPTRAP took place. The facility is being set up to deliver very clean and cooled beams of singly-charged recoil ions (Rare...     

Low Power Penalty Operation of a Wide Input Dynamic Range Cross-Phase Modulation Wavelength Converter

We successfully demonstrated low power penalty operation of a cross-phase modulated (XPM) wavelength converter using a semiconductor optical amplifier (SOA) power equalizer. We also clarified the SOA equalizing level for more adaptive wavelength conversion and achieved a power penalty of less than 1 dB over the wide input dynamic range of 15 dB.     

Controlled ring-opening polymerization of cyclic carbonates and lactones by an activated monomer mechanism

This article reviews recent topics in the controlled synthesis of polycarbonates and polylactones with small polydispersity indices by activated monomer cationic ring-opening polymerizations, especially with new initiator systems, such as alcohol/protonic acid and boron alkoxide/protonic acid. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2190–2198, 2002     

Use of various types of column reactors for flow-injection analysis.

Two or three different kinds of immobilized enzymes can be aligned in a minireactor so that sequential enzymatic reactions are carried out from upstream to downstream during flow-injection analysis. A lactate oxidase-catalase reactor, used as precolumn for removing pre-existing lactate in serum before the lactose dehydrogenase (LDH) reactions, was useful for the determination of serum LDH activity, which did not require any blank correction. A sequential glutamate dehydrogenase-glutamate oxidase reactor was also useful for a novel chemiluminometric determination of ammonia. On the other hand, a co-immobilized creatininase-creatinase-sarcosine oxidase reactor, in spite of containing creatininase which catalyses the reversible reaction, was the most efficient for the determination of serum creatinine.