01313nas a2200193   4500008004100000022001400041245004800055210004800103260007100151300001300222490000700235520067400242100002300916700002600939700002800965700002200993700002201015856008201037       2008                        eng d  a1083-616000aContinuous flow nitration of salicylic acid0 aContinuous flow nitration of salicylic acid  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a995-10000 v123 a<p>Continuous flow nitration of salicylic acid using HNO3/AcOH was studied in the SS316 tubular microreactor. At specific reaction conditions, complete conversion of the reactant was achieved in less than 7 min. It yielded only mononitro derivatives with a higher selectivity of 5-nitrosalicylic acid. Presence of the lower amount of acetic acid in the reaction mixture was seen to be detrimental, leading to precipitation of the desired product (5-nitrosalicylic acid). Reaction at higher temperatures yielded byproducts. The continuous mode operation using the system comprising the microdevices was demonstrated for 2 h with consistent composition at the outlet.</p>1 aKulkarni, Amol, A.1 aNivangune, Nayana, T.1 aKalyani, Vishwanath, S.1 aJoshi, Ramesh, A.1 aJoshi, Rohini, R.  uhttps://library.ncl.res.in/content/continuous-flow-nitration-salicylic-acid-001838nas a2200253   4500008004100000022001400041245009500055210006900150260007300219300001400292490000700306520092800313653002201241653001301263653003301276653001401309653001701323653002301340100002201363700002101385700002801406700002101434856012901455       2009                        eng d  a1566-736700aCatalytic synthesis of chalcone and flavanone using Zn-Al hydrotalcite adhere ionic liquid0 aCatalytic synthesis of chalcone and flavanone using ZnAl hydrota  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a1881-18880 v103 a<p>The Claisen-Schmidt condensation of 2'-hydroxy acetophenone and benzaldehyde to chalcone and flavanone show that calcined Zn-Al (6) hydrotalcite is active for this synthesis. Coating of ionic liquid `1-(tri-ethoxy-silyl-propyl)-3-methyl-imidazolium chloride' on Zn-Al hydrotalcites was accomplished employing incipient wetness process and on NaY, NaX, MK-5 and silica gel employing co-condensation methodology. Impregnated IL on calcined Zn-Al (6) catalysts were characterized by XRD, SEM, BET, (13)C and (27)Al NMR analysis and the activity of these catalysts were investigated for chalcone and flavanone synthesis. (27)Al CP MAS NMR technique was used to show that interaction of IL with hydrotalcite modifies the acid-base sites and is responsible for enhancement of catalyst activity. Several aromatic aldehydes were screened to assess the general applicability of the system. (c) 2009 Published by Elsevier B.V.</p>10a(27)Al CP MAS NMR10achalcone10aClaisen-Schmidt condensation10aFlavanone10aIonic liquid10aZn-Al hydrotalcite1 aKunde, Lalita, B.1 aGade, Swapna, M.1 aKalyani, Vishwanath, S.1 aGupte, Sunil, P.  uhttps://library.ncl.res.in/content/catalytic-synthesis-chalcone-and-flavanone-using-zn-al-hydrotalcite-adhere-ionic-liquid-001101nas a2200181   4500008004100000022001400041245004600055210004600101260007100147300001300218490000700231520050600238100002300744700002800767700002200795700002200817856008000839       2009                        eng d  a1083-616000aContinuous flow nitration of benzaldehyde0 aContinuous flow nitration of benzaldehyde  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a999-10020 v133 a<p>The nitration of benzaldebyde can be carried out in a safe manner in continuous mode using a microreactor system. Choice of a micromixer was seen to affect the performance of this two-phase reaction significantly The reaction time could he brought down to 2 min by increasing the reaction temperature and thereby taking advantage of higher heat transfer area. The simple T-micromixer is seen to be inefficient for two-phase reactions. Further scope of process intensification is also discussed.</p>1 aKulkarni, Amol, A.1 aKalyani, Vishwanath, S.1 aJoshi, Ramesh, A.1 aJoshi, Rohini, R.  uhttps://library.ncl.res.in/content/continuous-flow-nitration-benzaldehyde-001890nas a2200157   4500008004100000022001400041245009800055210006900153260007100222300001400293490000700307520124000314100002101554700002801575856012901603       2009                        eng d  a0888-588500aTwo-phase flow in minichannels: hydrodynamics, pressure drop, and residence time distribution0 aTwophase flow in minichannels hydrodynamics pressure drop and re  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a8193-82040 v483 a<p>Two-phase flow in mini-channels (1 mm x 1.5 mm x 430 mm and 1.5 mm x 0.5 mm x 430 mm serpentine channel geometry) made in different materials (SS 316, PMMA and Teflon) was studied at different flow rate ratio (0.66, 1.0 and 1.56) of the two immiscible fluids. A dual syringe pump was used to pump the fluids (air-water and water-kerosene) through the channels. For characterization of the two phase flow, experiments were carried out to measure the slug size distribution and relevant hydrodynamic properties, pressure drop across a single serpentine unit (i.e., one sinusoidal unit that includes two 180 degrees return bends connected by a straight portion of 20 mm) and also the residence time distribution of water. In all the cases, the effect of material of fabrication on the hydrodynamics was significant. Apart from flow rates and flow rate ratio of the two fluids, the slug size distribution was seen to have a strong effect of the channel orientation (vertical, horizontal) and also the flow direction (up-flow and down-flow). In the RTD studies, the response curve observed at the end of the channel was significantly different than the published literature. The reasons for such observations are discussed in detail.</p>1 aKulkarni, A., A.1 aKalyani, Vishwanath, S.  uhttps://library.ncl.res.in/content/two-phase-flow-minichannels-hydrodynamics-pressure-drop-and-residence-time-distribution-001372nas a2200253   4500008004100000022001400041245011500055210006900170260009800239300001200337490000700349520044200356653001500798653001400813653003900827653001200866653001200878653002700890653000900917100002200926700002800948700002100976856012100997       2010                        eng d  a0268-260500aDibutyltin oxide catalyzed aminolysis of oxalate to carbamate, oxamate and derivatives of imidazolidine trione0 aDibutyltin oxide catalyzed aminolysis of oxalate to carbamate ox  aTHE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLANDbJOHN WILEY & SONS LTDcMAY  a402-4070 v243 a<p>Catalytic aminolysis of oxalates by simple and substituted ureas has been shown to give carbamates, oxamates and derivatives of imidazolidine trione. Various substituted ureas and oxalates were screened to verify the applicability of the protocol. The role of dibutyltin oxide as catalyst, effect of solvent and reaction conditions on product distribution pattern has been discussed. Copyright (C) 2010 John Wiley &amp; Sons, Ltd.</p>10aAminolysis10acarbamate10aderivative of imidazolidine trione10aoxalate10aoxamate10atransfunctionalyzation10aUrea1 aKunde, Lalita, B.1 aKalyani, Vishwanath, S.1 aGupte, Sunil, P.  uhttps://library.ncl.res.in/content/dibutyltin-oxide-catalyzed-aminolysis-oxalate-carbamate-oxamate-and-derivatives-0