One-pot Synthesis of 1-Aryloxyacety l-4-(4'-nitrophenyloxyacetyl)-thiosemicarbazides under Phase Transfer Catalysis and Microwave Irradiation

The 1-aryloxyacetyl-4-(4-nitrophenyloxyacetyl)-thiosemicarbazides (3a-h) are synthe- sized via reaction of 4-nitrophenyloxyacetyl chloride with ammonium thiocyanate and aryloxyacetic hydrazides (2a-h) under phase transfer catalysis and microwave irradiation in excellent yield.

Synthesis of n-Butyl Acetate by Microwave Irradiation Under the Assistance of Solid-Liquid Phase Transfer Catalysis Without Solvent

Introduction Microwave irradiation has been very widely used in heating, cooking and brewing. Several papers which describe the use of domestic microwave ovens to perform rapid organic synthesis in solution have been published. The high heating efficiency gives rise to remarkable rate of reaction and dramatic reduction of reaction time. Nevertheless, its application seems to be limited to these procedures because of

Synthesis of diethers derived from furoin by phase transfer catalysis under microwave irradiation

A series of new diethers were obtained by alkylation of furoin under microwave irradiation （MWI） in phase transfer catalysis （PTC） conditions. The products of alkyl halides were synthesized in good yields （〉75%） within a few minutes, and the products of dihalides were synthesized in fair yields （about 45%）. The yields are dramatically improved compared to conventional heating under the same conditions, in spite of similar profiles of rising in temperature.

SOLID-LIQUID PHASE TRANSFER CATALYTIC SYN THESIS Ⅸ: THE SYNTHESIS OF α-AMINO ACIDS VIA ALICYLATION OF ALDIMINE UNDER MICROWAVE IRRADIATION,

The rapid alkylation of methyl N-benzylidene glycinate with halides under microwave irradiation using solid-liquid phase transfer condition without solvent has been achieved wilhin only one minute. After hydrolysis of alkylated products the corresponding α-amino acids were obtained in overall yield 43.6～62.5%.

Microwave Irradiation Promoted Synthesis of Aryloxy Acetic Acids

Several aryloxy acetic acids were synthesized under microwave irradiation. The factors, which affect the reaction, were investigated and optimized. It was revealed that the best yields(92.7%—97.4%) were obtained when the molar ratio of the reactants was n(ArOH)∶n(NaOH)∶n(ClCH 2CO 2H) =1∶2.5∶1.2 with microwave irradiation power of 640 W for 65—85 s.

Magnetic Nano Cobalt Ferrite Catalyzed Synthesis of 4H-Pyrano[3,2-h]quinoline Derivatives under Microwave Irradiation

A microwave irradiated magnetically separable nano cobalt ferrite catalyzed green method for the synthesis of 4-phenyl-4H-pyrano[3,2-h]quinolin-2-amine and 2-amino-4-phenyl-4H-pyrano[3,2-h] quinoline-3-carbonitrile derivatives through cyclization of aromatic aldehyde, acetonitrile/malononitrile and 8-hydoxyquinoline is developed and presented in this paper. The cubic magnetic cobalt ferrite nano particles were synthesized by sol-gel citrate precursor method and characterized by FT-IR, XRD, SEM and TEM techniques and the structures of the synthesized pyranoquinoline derivatives were assigned by IR, MASS and 1H NMR techniques. The reaction is carried out in a domestic microwave oven with a heat-resistant microwave safe glass container with a lid.

A rapid and efficient synthesis of indoloquinolinone and its analogues under microwave irradiation

A rapid and efficient method was established for the synthesis of indoloquinolinone and its analogues using acid-promoted cyclization in the present of PPA. All the reactions were completed in good yields in lOmin under microwave irradiation.

High-Efficiency Synthesis and Properties of Latent Pigment Red 272DPP-BOC by Microwave Irradiation

A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results revealed that irradiation of microwaves (MWs) for several seconds to 272 DPP in NMP (N-methyl-2-pyrrolidone) solvent yielded DPP latent pigment (272DPP-BOC) at a high yield of 86.2%. Two kinds of latent-pigment crystals, namely, red and yellow, were obtained by recrystallization, and it was found that the fluorescence-emission properties of the two kinds differ significantly. Single-crystal X-ray structural analysis showed that the difference in the fluorescence-emission properties of the two types is derived from the difference in their crystal structures.

Synthesis and Crystal Structure of 1,7,7-Trimethyl-4-(4-methoxyphenyl)-4,6,7,8-tetrahydroquinoline-2,5(1H,3H)-diones under Microwave Irradiation

The title compound （C19H23NO3） was synthesized by the one-pot reaction ofp-methoxybenzaldehyde, Meldrum＇s acid, dimedone and CH3NH3Cl （NaOAc） in ethanol under microwave irradiation without catalyst and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 8.7462（10）, b = 17.7367（19）, c = 11.5959（14） A, β = 110.981（3）°, V= 1679.6（3） A^3, Z = 4, Dc = 1.239 g/cm^3,μ（MoKa） = 0.083 mm^-1, F（000） = 672 and Mr = 313.38. The structure was refined to R = 0.0530 and wR = 0.1216. X-ray analysis reveals that the dihedral angle between plane 1 （N（1）, C（1）, C（2）, C（3）） and plane 2 （C（1）, C（2）, C（6）, C（7）, C（9）） is 3.64°, andt hat between plane 2 and plane 3 （C（11）～C（16）） is 85.33°.

Synthesis of Poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] and Poly(2,5-benzimidazole) by Microwave Irradiation

A rapid way assisted by microwave irradiation was proposed to synthesize poly[2,2＇-（m-phenylene）-5,5＇-bibenzimidazole]（PBI） and poly（2,5-benzimidazole）（ab-PBI）.Synthesis of PBI in polyphosphoric acid is conducted for 20 h or even more.Under microwave irradiation,the polycondensations could be completed in polyphosphoric acid within 3 h from 3,3＇-diaminobenzidine tetrahydrochloride（DAB·4HCl·2H2O） and isophthalic acid for PBI,and from 3,4-diaminobenzoic acids（DABA） for ab-PBI,respectively.The conditions for the polymerization including the power of microwave irradiation,temperature,heating time,and concentrations of the reactants in polyphosphoric acid were optimized.The inherent viscosity of the polymers in concentrated sulfuric acid at 30 ℃ was 0.9766 dL/g for PBI,and 0.6480 dL/g for ab-PBI,respectively.Characterization of the polymer products was made by nuclear magnetic resonance（1^H NMR）,Fourier transform infrared spectra（FTIR） and thermogravimetric analysis（TGA）.

Synthesis and Crystal Structure of N-methyl-9-(4-bromophenyl)-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione under Microwave Irradiation

The crystal structure N-methyl-9-(4-bromophenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10- decahydroacridine(C20H20BrNO2) was determined by single-crystal X-ray diffraction analysis. It belongs to P21/n space group, with a = 10.7999(18), b = 13.845(3), c = 11.4031(3) ?, β = 99.324(4)°, Dc = 1.525 g/cm3, Z = 4, λ = 0.71070 ?, μ(MoKα) = 2.455 mm-1, Mr = 386.28, V = 1682.5(5) ?3, F(000) = 792, the final R = 0.0463 and wR = 0.1053. In the crystal structure, the pyridine ring adopts a boat conformation, the two six-numbered rings fused with pyridine ring adopt twisting boat con- formation.

Synthesis of Novolacs under Microwave Irradiation

Novolacs were successfully synthesized using oxalic acid as the catalyst in a self-designed device based on a domestic microwave oven, The fundamental characteristics of the synthesis of novolacs under microwave irradiation （MI） were investigated, and the properties of the resins polymerized and dehydrated under microwave irradiation and conventional heating （CH） were analyzed comparatively, The results show that MI reduced the polymerization and dehydration time greatly; and that the resins polymedzed and dehydrated under MI presented longer flow distances （ i. e., higher flowability） and shorter cure time than those obtained under CH.

Microwave-assisted synthesis of asymmetric thiocarbonohydrazones under solvent-free conditions

Six new asymmetric thiocarbonohydrazones 3a-3f were synthesized from following steps： firstly hydrazine hydrate reacted with carbon disulfide to form thiocarbonohydrazide （1） under microwave irradiation. Then compound （1） reacted with ketone and different aldehydes step by step to give 3a-3f with excellent yields under solvent-free conditions using microwave irradiation. Their structures have been determined by elemental analysis, IR, MS and ^1H NMR data. 2009 Qing Han Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Comparison of Conventional and Microwave-assisted Synthesis and Characteristics of Aluminum-pillared Rectorite

The synthesis and characterization of aluminum-pillared rectorite were studied. The synthesis was conducted with both conventional heating and microwave irradiation. Microwave irradiation was found to enhance the intercalation and ion-exchange during synthesis, and to be able to produce the rectorite with a larger d_(001) and a better uniformity. The specific surface area is 180 m^2/g and basal spacing is 3.2 nm. The texture change and thermal and hydrothermal stability of cross-linked rectorite were examined using XRD, FTIR, nitrogen-adsorption and TGA. The experimental results show that the aluminum-pillared rectorite, after calcined at 800 ℃ for 3 hours, can keep the basal aluminum-silicate texture and would not disperse in water at room or an elevated temperature. The aluminum-pillared rectorite shows a high specific surface area, good thermal and hydrothermal stability, and is promising in applications as catalyst carriers and adsorbents for waste treatment.

Synthesis of Modified β-Zeolite Under Microwave Irradiation and Its Use on Etherification

zeolite was synthesized by using tetraethyl ammonium hydroxide as the template reagent andmicrowave radiation as the heat source. The effect of the sol composition and the radiation temperature onzeolite crystallinity was investigated. The zeolite was tested and compared with the commercial product, whichwas produced by conventional hydrothermal synthesis method. The physico-chemical properties of the syn-thesized samples, the specific surface area of the samples synthesized under microwave irradiation and porevolume measured by X-ray diffraction apparatus, were better than the conventional samples. The etherificationexperiment on FCC light naphtha in the presence of transition metals modified Hβ-zeolite, which was synthe-sized firstly under microwave irradiation, was studied in a fixed-bed reactor. The effect of catalyst preparationconditions on its activity, stability and the effect of reaction temperature, methanol/tertiary-carbon olefin molarratio and liquid hourly space velocity on the etherification reaction were discussed. The experimental resultsshowed that the different metals modified Hβ-zeolite had different etherification performances. And theconversion of tertiary carbon-olefins of the molybdenum modified Hβzeolite, which was loaded at a concen-tration of 3 percents, was higher than that on 6.0 percent of Hβzeolite. The modified Hβzeolite catalystspossessed favorable prospects for its higher stability.

Synthesis and Crystal Structure of N-cyclopropyl-9 -(3,4-dicholophenyl)-1,2,3,4,5,6,7,8,9,10-decahydroacridine -1,8-dione under Microwave Irradiation

The N-cyclopropyl-9-(3,4-dicholophenyl)-1,2,3,4,5,6,7,8,9,10-decahydroacri- dine-1,8-dione was synthesized by the reaction of 1,3-cyclohexanedione, N-cyclopropylamine and 3,4-dicholoaldehyde in water and glycol under microwave irradiation. Its crystal structure was determined by single-crystal X-ray diffraction analysis. It possesses P212121 space group, with a = 9.9103(5), b = 13.3597(8), c = 14.5633(8) ?, V = 1928.16(18) ?3, Mr = 402.30, Z = 4, Dc = 1.386 g/cm3, λ = 0.7107 ?, μ(MoKα) = 0.354 mm?1 and F (000) = 840. The structure was refined to R = 0.0280 and wR = 0.0757. In the structure, the pyridine ring adopts a boat conformation.

Synthesis and Crystal Structure of Ethyl 4-(3,4-Methylenedioxylphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyridine-5-carboxylate under Microwave Irradiation

The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction.The crystal is of monoclinic,space group C2/c with a=18.520(2),b=7.8910(1),c=21.728(3)?,β=104.77(1)°,V=3070.4(7)?^3,Mr=303.31,Z=8,Dc=1.312g/cm^3,λ=0.71073?,μ(MoKα)=0.098mm^-1 and F(000)=1280.The structure was refined to R=0.0486 and wR=0.1287.There exist intermolecular hydrogen bonds in the crystal.

Synthesis of 3-Alkyl-5-Benzylidene-2,4-Thiazolidinedione Under Microwave Irradiation

Microwave irradiation of aromatic aldehyde and 2,4-thiazolidinedione provides a fast and high-yield access to 5-benzylidene-2,4-thiazolidinedione. Seven 3-alkyl-5-benzylidene-2,4-thiazolidinedione compounds were produced with high yield by reacting 5-benzylidene-2,4-thiazolidinedione with different alkylating agents under microwave irradiation.

Microwave-prompted Rapid and Efficient Synthesis of Diacyl Thiosemicarbazides and Semicarbazides in Solvent and Catalyst Free Condition

Eighteen 1-aroyl-4-（2-iodobenzoyl）thiosemicarbazides and corresponding semicarbazides were synthesized in excellent yield under microwave irradiation in solvent and catalyst free condition.