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Microwave ovens, and

The other attraction is the method itself clay, a Sears microwave oven and the most lightning-quick results ever imagined Someone sent Strike this method via fax, but dumbass Strike did not get the person s name . But you know who you are. Bra ... [Pg.123]

Polycarbonates based on tetramethylbisphenol A are thermally stable and have a high Vicat softening point of 196°C. On the other hand they have lower impact and notched impact resistance than the normal polymer. Blends with styrene-based polymers were introduced in 1980, and compared with PC/ABS blends, are claimed to have improved hydrolytic resistance, lower density and higher heat deflection temperatures. Suggested applications are as dishes for microwave ovens and car headlamp reflectors. [Pg.579]

A university student recently had a busy day. Each of the student s activities on that day (reading, having a dental x-ray, making popcorn in a microwave oven, and getting a suntan) involved radiation from a different part of the electromagnetic spectrum. Complete the following table and match each type of radiation to the appropriate event ... [Pg.174]

Li and co-workers introduced a rapid and efficient microwave-assisted method to prepare new disubstituted 1,3,4-thiazoles from 1,4-disubtituted thiosemicarbazides with the objective to obtain biologically active molecules. The intermediate l-aryloxyacetyl-4-(4-methoxybenzoyl)thiosemicarbazide was irradiated in an excess of glacial acetic acid in a domestic microwave oven and led to the formation of 2-(methoxybenzoyl-5-aryloxymethyl)-l,3,4-dithiazoles in good yields [30] (Scheme 20). [Pg.72]

Since 1986, when the very first reports on the use of microwave heating to chemical transformations appeared [147,148], microwave-assisted synthesis has been shown to accelerate most solution-phase chemical reactions [24-27,32,35]. The first application of microwave irradiation for the acceleration of reaction rate of a substrate attached to a solid support (SPPS) was performed in 1992 [36]. Despite the promising results, microwave-assisted soHd-phase synthesis was not pursued following its initial appearance, most probably as a result of the lack of suitable instriunentation. Reproducing reaction conditions was nearly impossible because of the differences between domestic microwave ovens and the difficulties associated with temperature measurement. The technique became a Sleeping Beauty interest awoke almost a decade later with the publication of several microwave-assisted SPOS protocols [37,38,73,139,144]. There has been an extensive... [Pg.89]

A semiconductor microcircuit is a series of electrically intercoimected films that are laid down by chemical reactions. The successful growth and manipulation of these films depend heavily on proper design of the chemical reactors in which they are laid down, the choice of chemical reagents, separation and purification steps, and the design and operation of sophisticated control systems. Microelectronics based on microcircuits are commonly used in such consumer items as calculators, digital watches, personal computers, and microwave ovens and in information processing units that are used in communication, defense, space exploration, medicine, and education. [Pg.53]

Two lots of oranges of the Navel I and II type imported from (jreece, were used in this study. The peels were removed, then finely cut and processed following two procedures part of them were dried in the laboratory drier at 60°C, while the rest were pretreated in a microwave oven and then dried in a laboratory drier at 60 °C. [Pg.941]

In this study we show that the Pd/C catalyzed Suzuki-Miyaura coupling reaction can be performed in a microwave oven. Overall the microwave synthesis is faster than comparable thermal methods and the combination of the ease of use of the microwave oven and the facile work-up with Pd/C makes this a very efficient method for performing coupling reactions. [Pg.482]

A solvent-free synthesis of benzo[b]furan derivatives 10-79, a class of compounds which is often found in physiologically active natural products, was described by Shanthan Rao and coworkers. These authors heated phosphorane 10-71 for 8 min in a microwave oven and obtained the benzo[b]furan 10-74 in 73% yield (Scheme 10.18) [25]. The sequence is initiated by an intramolecular Wittig reaction, providing alkyne 10-72 this underwent a subsequent Claisen rearrangement to give the intermediate 10-73. Also in this case, normal oil-bath heating gave much lower yields (5%) of the desired product the authors hypothesize that the micro-... [Pg.576]

After some considerations relating to microwave technology, we will examine microwave ovens and reactor background. The limits of domestic ovens and temperature measurements will be analyzed, as well as design principles of microwave applicators. Next, a brief overview of laboratory, experimental and industrial equipment will be given. [Pg.19]

The reaction was performed by heating the reagents at 150 °C for 10 h in o-xylene. The desired exo adduct was obtained with high stereoselectivity and subsequent formation of the diastereoisomer 58 was considered to occur by isomerization of the exo adduct. The reaction was dramatically accelerated by use of microwave irradiation in a domestic microwave oven, and the carboxylic acid was obtained after 45 min with a small increase in stereoselectivity (Scheme 9.15) [57]. [Pg.306]

Several manufacturers supply microwave ovens and digestion bombs (Tables 14.6 and 14.7). CFM Corporation state that their solid PTFE bombs are suitable for the digestion of soils and sediments. [Pg.445]

Fast, solid state, microwave-assisted, synthesis. A short history of reactions carried out in the solid state under the influence of microwaves was reported by Kniep (1993) who presented this technique as characteristic of a fast solid-state chemistry and described the preparation of CuInS2 by using a method first developed by Whittaker and Mingos (1992) and extended by Landry and Barron(1993). Copper, indium and sulphur (all powders between 100 and 300 mesh) in a molar ratio 1 1 2 were thoroughly mixed and loaded into a silica ampoule. This, sealed under vacuum, was placed in a domestic microwave oven and irradiated at 400 W and 2450 MHz. [Pg.573]

Put the balloon in the microwave oven and cook at full power for however many seconds it takes for boiling to begin, which is indicated by a rapid growth in the size of the balloon. It may take only about... [Pg.24]

A similar rapid microwave one-pot synthesis of substituted quinazolin-4-ones was also reported, which involved cyclocondensation af anthranilic acid, formic acid (or an orthoester) and an amine under solvent-free conditions (Scheme 3.37)61. A complimentary approach was adopted to synthesise 4-aminoquinazolines in very good yields, involving the reaction of aromatic nitrile compounds with 2-aminobenzonitrile in the presence of a catalytic amount ofbase (Scheme 3.38)62. The reactions were performed in a domestic microwave oven and required only a very short heating time. A microwave-assisted synthesis of a variety of new 3-substituted-2-alkyl-4-(3H)-quinazolinones using isatoic anhydride, 2-aminobenzimidazole and orthoesters has also been described (Scheme 3.38)63. [Pg.62]

Hydro acylation of alkenes was achieved in the presence of Wilkinson s catalyst and microwave irradiation under solvent-free conditions. As an example, benzaldehyde was reacted with dec- 1-ene to give 1-phenylundecan- 1-one in 83%yield within 30 min. Both domestic microwave ovens and single-mode reactors have been used for this reaction. The presence of an amine such as 2-amino-3-picoline or aniline and a carboxylic acid is crucial for the success of the reaction, showing that the formation of an imine plays an important role as an intermediate in the mechanism of this reaction29. [Pg.80]

In a typical experiment, 1 mmol of resin bound amine, 25% excess of anhydride were mixed with 1 g of activated silica gel and 10 mol% of Ti02-doped silica gel. This mixture was placed in a beaker in the centre of a domestic microwave oven and irradiated for 1 min intervals (5-7 min overall) with thorough agitation after each step. The resin-silica gel mixture was allowed to cool to room temperature prior to cleavage. The product was cleaved from the resin-silica gel mixture by treatment with 2 x 10 ml of 33% TFA in DCM. After filtration and evaporation of the solvent, the corresponding imides were obtained in moderate to good yields. [Pg.213]

This book will concentrate on the chemistry and fundamental chemical engineering principles needed for integrated-circuit (IC) manufacture. Integrated circuits are currently used in consumer items, such as hand-held calculators, digital watches, microwave ovens, and automobiles, and in microprocessors for communication, defense, education, medicine, and space exploration. Naturally, new application areas are continually being developed. [Pg.14]

Freshly prepared NaBH4-alumina (1.13 g, 3.0 mmol of NaBH4) is thoroughly mixed with neat acetophenone Id (0.36 g, 3.0 mmol) in a test tube and placed in an alumina bath inside the microwave oven and irradiated (30 s). Upon completion of the reaction, monitored on TLC (hexane-EtOAc, 8 2, v/v), the product is extracted into ethylene chloride (2x15 mL). Removal of solvent under reduced pressure essentially provides pure sec-phene thy 1 alcohol 2d in 87% yield. No side product formation is observed in any of the reactions investigated and no reaction takes place in the absence of alumina. [Pg.8]

In a typical experiment, benzaldehyde (106 mg, 1 mmol) was added to the finely powdered paraformaldehyde (60 mg, 2 mmol). To this mixture, powdered barium hydroxide octahydrate (631 mg, 2 mmol) was added in a glass test tube and the reaction mixture was placed in an alumina bath (neutral alumina 125 g, mesh 150, Aldrich bath 5.7 cm diameter) inside a household microwave oven and irradiated for the specified time at its full power of 900 W intermittently or heated in an oil bath at 100-110 °C. On completion of the reaction, as indicated by TLC (hexane-EtOAc, 4 1, v/v), the reaction mixture was neutralized with dilute HC1 and the product extracted into ethyl acetate. The combined organic extracts were dried over anhydrous sodium sulfate and the solvent removed under reduced pressure. The pure benzyl alcohol (99 mg, 91%), however, is obtained by extracting the reaction mixture with ethyl acetate prior to neutralization and subsequent removal of the solvent under reduced pressure. [Pg.9]


See other pages where Microwave ovens, and is mentioned: [Pg.323]    [Pg.338]    [Pg.463]    [Pg.1220]    [Pg.301]    [Pg.32]    [Pg.308]    [Pg.67]    [Pg.3]    [Pg.9]    [Pg.13]    [Pg.57]    [Pg.328]    [Pg.20]    [Pg.307]    [Pg.409]    [Pg.504]    [Pg.253]    [Pg.259]    [Pg.240]    [Pg.149]    [Pg.698]    [Pg.539]    [Pg.238]    [Pg.320]    [Pg.10]    [Pg.65]    [Pg.323]    [Pg.665]    [Pg.110]    [Pg.209]   


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