Amide Ionic Liquids(AILs)/L-Proline Synergistic Catalyzed Asymmetric Mannich Reactions

Amide ionic liquids （MLs）/L-proline synergistic catalyzed Mannich reactions of isovaleraldehyde, methyl ketones, and aromatic amines were carried out in moderate to high yields （ up to 96% ） and high stereo selectivities （ 〉99% e. e. ）. The products were easily isolated by extraction; and the catalyst system was readily recycled at least thrice without significant loss of efficiency. The scope of the substrates was studied and the interpretation of the manifest improvement of the reaction rates and enantio-selectivity of the novel catalyst system was speculated.

Isosteviol-amino Acid Conjugates as Highly Efficient Organocatalysts for the Asymmetric One-pot Three-component Mannich Reactions

Isosteviol-amino acid conjugates were synthesized and used as chiral catalysts for the asymmetric three-component Mannich reaction with hydroxyacetone as donor molecule. Good yields （up to 98%） and excellent stereoselectivities （up to 97 ： 3 dr and 99% ee） were achieved in a short reaction time. In addition, syn- or anti-configurations of a-hydroxy-β-amino carbonyl compounds were obtained as main products with different chiral catalysts.

Scope and Limitations of Optical Pure Hydantoins as Chiral Auxiliaries in Asymmetric Mannich Reactions

The Mannich reaction of various 5-substituted and N-acyl substituted chiral hydantoins with a series of aldimines smoothly occurred with full stereochemical control. These Mannich adducts have been cleaved by alcoholysis to afford several synthetically useful chiral building blocks like β-amino esters and β-lactams in good yields and in enantiopure form.

A New Approach on Modification Reactions of Atherton-Todd, Betti, Mannich and Doebner with Arsine, Stibine and Bismuthine in Organometallic Chemistry

A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions can be used for the synthesis of drugs and biologically active organic compound of arsenic, antimony and bismuth. A possible new mechanism of the reaction is proposed.

Synthesis and Crystal Structure of the Derivative of Hydroquinone from Mannich Reaction

The regioselective Mannich-type aminomethylation of hydroquinone afforded a nitrogen-containing compound, 2,5-bis-(morpholinomethyl)hydroquinone A, and its crystal structure was determined by single-crystal X-ray diffraction. Crystal data for A: C16H24N2O4, Mr = 308.37, orthorhombic, space group Pbca, a = 10.479(4), b = 10.298(4), c = 14.865(5) ?, V = 1604.3(11) ?3, Z = 4, Dc = 1.277 g/cm3, F(000) = 664, μ = 0.092 mm-1, GOF = 1.078, the final R = 0.0508 and wR = 0.1075 for 1416 observed reflections with I > 2σ(I). There exist two intramolecular O–H…N hy- drogen bonds between the phenolic O atoms and the morpholine N donors and the morpholino rings assume the preferred chair conformation.

CeCl_3·7H_2O as an efficient catalyst for one-pot synthesis of β-amino ketones by three-component Mannich reaction

Cerium trichloride heptahydrate(CeCl_3·7H_2O) was found to be an efficient and recyclable catalyst for the three-component direct Mannich reaction of anilines and benzaldehydes with acetophenone.This protocol has advantages of high yield,no environmental pollution,mild condition,and simple work-up procedure.

A New Investigation of Mannich Reaction

During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of product IM is postulated and discussed on the basis of deuterium labelling.

Theoretical Studies on the Mechanism of Mannich Reaction Involving Iminium Salt as Potential Mannich Reagent(1)--Use Acetaldehyde as Pseudo-acid Component

This paper is one of a series of reports of theoretical researches on the mechanism of the Mannich reaction using the iminium salt as the potential Mannich reagent. According to the results of AM1 dynamic calculations, the activation energies of key steps in conventional Mannich reactions between ammonia, formaldehyde and acetaldehyde in neutral and acidic media are 438 8 kJ/mol and 393 9 kJ/mol respectively. The activation energy of the rate controlling step of the Mannich reaction which contains the potential Mannich reagent is 274 7 kJ/mol. Therefore, it can be derived that the potential Mannich reagent can increase the rate of the reaction remarkably. The reasons for this have been discussed in terms of the orbital match and electrostatic interaction between the atoms of reactant complexes. In this paper another different conjectured mechanism of the potential Mannich reagent which can reduce the activation energy is considerably studied.

Synthesis and NO production inhibition of novel Mannich base derivatives of irisolidone

Five new C-8 Mannich base derivatives of irisolidone 2a-2e were synthesized and their nitric oxide（NO）production inhibitory activity was evaluated.Compounds 2a,2b,2c and 2e displayed stronger activities in vitro than the parent compound irisolidone.

COMBINATORIAL SYNTHESIS OF MANNICH BASES IN SOLUTION/POLYMER REAGENT WORKUP

This paper describes a combinatorial Synthesis of the Mannich Bases in Solution through the Mannich reaction using 3 ketones, 5 amines and formaldehyde in solution and hydrochloride as a catalyst and then using a macroporous quarterized ammonium resin (CO32- form) as a scavenge agent to remove the acid catalyst when the Mannich reaction is completed. It was found by GC/MS analysis that the symmetrical ketone, such as acetone, in the Mannich reaction mainly produces one Mannich base; while the asymmetrical ketone, such as 2-pentanone, gives two Mannich bases. The reactivity depends on the tereo-hinder of both ketones and amines.

A New One-Pot Synthesis of Macroheterocycles Using Mannich Reaction

Three N,N-heterylmethyl derivates of diaza-18-crown-6(I) are readily prepared by the reaction of (I) with paraformaldehyde and heterocyclic compounds in dry benzene.

Effect of Polyethyleneimine Assisting the Growth of Eu-doped ZnO Nanowire Arrays in Mannich Reaction

In study on the growth reaction mechanism of Eu-doped ZnO nanowire（NW）, the intermedium of reaction is characterized by measures such as FTIR. Besides, the influences of polyethyleneimine（PEI） on morphology, structure and photoelectric property of NW are observed by SEM, TEM, XRD, UV-vis and PL spectrum. According to the result, it manifests that Eu-doped ZnO NW array growth response experiences six mutually associated reaction processes in PEI-HMTA system：（a） chelation reaction of PEI and Zn^2＋ ＆ Eu^3＋;（b） protonation reaction of PEI and NH_3;（c） decomposition reaction of hexamethylenetetramine（HMTA）;（d） Mannich reaction of HCHO and PEI;（e） formation of precursor of Eu-doped ZnO;（f） dehydration condensation of Eu-doped ZnO precursors, further forming a doped ZnO NW array. Among them, PEI is the key factor of the whole doping growth reaction process. It both plays a role in modifying the growth of ZnO NW and makes it become longer and thinner. In the meantime, it also facilitates doping of Eu and enables ZnO NW to capture more photoelectrons and higher transmission rate, which is critical to improve photovoltaic performance of optoelectronic devices.

Synthesis of new 2,5-dimethyl pyrrole derivatives from acetonylacetone

Acetonylacetone 1 was treated with thiourea,aniline,glycine and glutamic acid to give pyrrole derivatives 2,3,5,and 9 by Paal-Knorr reaction,respectively.Then 3 was successfully transformed into the related pyrrole derivative 4 by Mannich reaction. Compounds 6,7 and 8 were obtained by reacting 5 with phenethyl alcohol,phenylallylic alcohol and leaf alcohol by esterification reactions,respectively.The structures of all new products were elucidated by IR,NMR and HRMS spectra.

STUDY ON SYNTHESIS OF AMPHOTERIC POLYACRYLAMIDE IN INVERSE EMULSION

Amphoteric polyacrylamide was prepared first by the copolymerization of acrylamide with sodium acrylate and then through Mannich reaction.The copolymerization was carried out with a redox initiation system using the method of inverse emulsion polymerization.In this paper the reaction conditions and factors that affect emulsion stability were studied.Experiments show that a stable latex can be obtained under the following conditions:anionic degree is five percent,the ratio among acrylamide,formaldehyde and dimethylamine is 1∶1∶1.2,reaction temperature is 45 ℃,reaction time lasts four hours,and pH equals 5.0.The amphoteric copolymer has a higher molecular weight and cationic degree,so it is an ideal filler retention and drainage aid in paper making.

Ultrasonicwave-assisted tandem-reaction for synthesis of symmetrical vicinal diamines

A practical synthesis of symmetrical vicinal diamines with broad chemistry scope is described. The key step is the ultrasonicwave promoted tandem-reaction, two-step reaction sequence combining Mannich double condensations with benzo- triazole, glyoxal and primary or secondary amines and reduction of the bis（benzotriazole）-adducts with sodium borohydride proceeded smoothly in tetrahydrofuran in high yield at room temperature.

Synthesis and Crystal Structure of a N,N,N′-tri(2-hydroxy-5-methylbenzyl)-1,2-ethanediamine

An aminophenol ligand, N,N,N＇-tri（2-hydroxy-5-methylbenzyl）-l,2-ethanediamine, was prepared through the Marmich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffraction. The title compound （C26H32N2O3, Mr = 420.54） belongs to the monoclinic system, space group P21/n with a = 8.6233（14）, b = 10.2655（16）, c = 26.017（4） A, β = 95.797（2）°, V = 2291.3（6） A^3, Z = 4, the final R = 0.0461 and wR = 0.1139 for 4267 unique reflections （Rint = 0.028） with 11691 observed ones （I〉 2a（I））.

6,8-Di-tert-butyl-3-(2,4-dimethyl-quinolin-7-yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine: Synthesis, Crystal Structure and Luminescent Properties

6,8-Di-tert-butyl-3-（2,4-dimethyl-quinolin-7-yl）-3,4-dihydro-2H-benzo[e][1,3]oxa- zine（1） was obtained by one-pot reaction starting from 2,4-di-tert-butylphenol, 7-amino-2,4- dimethyl-quinoline and paraformaldehyde. The compound was structurally characterized by NMR, IR and single-crystal X-ray diffraction along with the elemental analysis. Compound 1 crystallizes as solvate with chloroform. The solvate 1·CHCl3（C28 H35 Cl3 N2 O, Mr = 521.93） belongs to the triclinic system, space group P1 with a = 10.852（2）, b = 11.352（2）, c = 13.050（3）, α = 101.95（3）, β = 92.94（3）, γ = 114.64（3）o, V = 1412.4（5）3, Z = 2, Dc = 1.227 g/cm3, F（000） = 552, μ = 0.347 mm–1, R = 0.0959 and wR = 0.2725（I 〉 2？（I））. The chloroform molecule displays a rotational disorder as one chloro atom can be located at two different positions. The packing of 1·CHCl3 was further stabilized by intramolecular C–H…O interactions, intermolecular C–H…N interactions, C–H…π interactions, and π…nteractions. The luminescent properties of compound 1 in both methylene chloride solution and the solid state were studied.

New Approach to Synthesis of Tetrahydroisoquino[2,l-c] [1,3]-benzodiazepine

A concise and efficient synthesis of the new compounds tetrahydroisoquino [2,1-c] [1,3] benzodiazepine 5 and 7 is reported.

Properties of a High Hydrolysis Stable Nitrogenous Benzo-heterocyclic Borates

A benzotriazole-containing derivative was synthesized via the Mannich reaction.The structure was characterized by NMR spectroscopy.By utilizing computational chemistry and molecular simulation,the calculation and mapping of atomic charge and frontier molecular orbitals with complex structure of the borate were carried out.The acid number of BTBE(nitrogen-containing heterocyclic borate)was determined by the standard test method for acid number and the open observation method.The results showed that BTBE had a low initial acid number,because the acid number was changed only after 72 hours of hydrolysis,and it was negative after the hydrolysis reached 120 hours.The extreme-pressure friction resistance of BTBE and other four base oils was also determined.For 5 kinds of base oils,the friction experiment was carried out under a load of 30 kgf,and the BTBE showed a lowest wear scar diameter(0.365 mm)along with a highest maximum non-seizure load.The results showed that the EP friction resistance of BTBE was stronger than that of other four base oils under the same test conditions.The results of hydrolysis performance showed that the synthesized nitrogencontaining heterocyclic borate had a high resistance to hydrolysis,while demonstrating broad application prospects.

The Rearrangement of 2-Benzothiazolylthioacetyl Hydrazide in Synthesis of s-Triazolo[3,4-b]benzothiazole-3-thiol

The rearrangement reaction of 2-benzothiazolylthioacetyl hydrazide 1 with potassium hydroxide and carbon disulfide in ethanol to produce s-triazolo[3, 4-b]benzothiazole-3-thiol 3 was described. 3 also can be obtained from 2-benzothiazolylhydazine 2 and the two methods for getting 3 were compared. Mannich reaction of compounds 3 was reported too.