Syntheses and Structural Characterization of Dimethyltin Complexs of N-(3-Methoxysalicylidene)-α-amino Acid

Three new dimethyltin complexes of N-（3-methoxysalicylidene）-α-amino acid,（CH3）2Sn（3-CH3O-2-OC6H3CH=NCHRCOO）（R = H,1;CH3,2;（CH3）2CH,3）,have been synthe-sized by treating dimethyltin dichloride with the potassium salt of the ligand and characterized by elemental analysis,IR and 1H NMR spectra.The crystal structure of [（CH3）2Sn（3-CH3O-2-OC6H3CH=NCH2COO）（CH3OH）]2 H2O（1a）,formed from methanol solution of 1,has been deter-mined.The crystal belongs to the monoclinic system,space group C/2c with a = 20.636（3）,b = 7.8854（9）,c = 20.668（2） ,β= 113.265（2）°,V = 3089.7（6） 3,Z = 4,Dc = 1.707 g/cm3,= 1.675 mm-1,F（000） = 1592,R = 0.0301 and wR = 0.0841.In complex 1a,the tin atom is six-coordinate and possesses a distorted [SnC2NO3] octahedral geometry with the two methyl groups occupying the trans positions.The weak Sn O interactions and intermolecular hydrogen bonds connected the molecules into an infinite chain.

1,5-Dimethy-4-[(3-nitro-benzylidene)-amino]-2-pheyl-1,2-dihydro-pyrazol-3-one

The title compound C18H16N4O3 （Mr = 336.35） has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Schiff base compound is a derivative of 4-aminoantipyrine. As expected, the molecular structure adopts a trans configuration about the central C=N double bond. It crystallizes in orthorhombic, space group P2dc with a = 7.632（1）, b = 7.816（1）, c = 28.082（5） A,β = 96.18（1）°, V= 1665.48（51） A^3, Z= 4, Dc = 1.341 g/cm^3, F（000） = 704,μ = 0.094 mm^-1, the final R = 0.0448 and wR = 0.1058. Of the total 3748 collections, 3105 were unique. In the molecule there exist two different planes of pyrazoline and C（11）-C（16） phenyl ring, which are approximately coplanar （r.m.s. de deviation from the combined mean plane is 0.03 A） with the dihedral angle between them of 9.8%.

4-[(Furan-2-ylmethylene)-amino]-1,5-dimethyl-1,2-dihyl-1,2-dihydo-pyrazol-3-one

The title compound （C16H15N3O2, Mr= 281.31） has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Schiff base compound is a derivative of 4-aminoantipyrine. As expected, the molecular structure adopts a trans configuration about the C=N double bond. It crystallizes in the monoclinic system, space group P2 1/c with a = 11.150（3）, b = 9.906（3）, c = 13.624（4） A, β = 106.360（4）°, V= 1443.9（7） ,A^3, Z = 4, Dc = 1.294 g/cm^3, F（000） = 592,μ（MoKa） = 0.088 mm ^-1, R = 0.0577 and wR = 0.1214. Of the 5766 total reflections, 2540 were unique. In the molecule there exist two different planes of pyrazoline and O（2）-C（10） phenyl ring, which are approximately coplanar （r.m.s. de deviation from the combined mean plane is 0026 A） with the dihedral angle between them of 6.3°.

3-氨基邻苯二甲酰肼的简便合成

以邻苯二甲酸酐为原料,经硝化、脱水、肼化、还原等步骤合成了3-氨基邻苯二甲酰肼。

PEG-OSO_3H as an efficient and recyclable catalyst for the synthesis of β-amino carbonyl compounds via the Mannich reaction in PEG-H_2O

Sulfuric acid-modified polyethylene glycol 6000（PEG-OSO_3H） was applied as an efficient and recyclable catalyst for the synthesis ofβ-amino carbonyl compounds via the Mannich reaction between aldehydes,aromatic ketones and aromatic amines at room temperature using PEG400-H_2O（1：1） as environment-friendly solvents.The reactions were completed in short times and mild reaction conditions with good to excellent yields.

Cyclooxygenase-2 inhibitor inhibits hippocampal synaptic reorganization in pilocarpine-induced status epilepticus rats

Objective： To examine modulations caused by cyclooxygenase-2 （COX-2） inhibitors on altered microenvironments and overbalanced neurotransmitters in pilocarpine-induced epileptic status rats and to investigate possible mechanisms. Methods： Celecoxib （a COX-2 inhibitor） was administered 45 min prior to pilocarpine administration. The effects of COX-2 inhibitors on mlPSCs （miniature GABAergic inhibitory postsynaptic currents） of CA3 pyramidal cells in the hippocampus were recorded. Expressions of COX-2, c-Fos, newly generated neurons, and activated microgliosis were analyzed by immunohistochemistry, and expressions of c^-subunit of y-amino butyric acid （GABAA） receptors and mitogen-activated protein kinase/extracellular signal-regulated protein kinase （MAPK/ERK） activity were detected by Western blotting. Results： Pretreatment with celecoxib showed protection against pilocarpine-induced seizures. Celecoxib prevented microglia activation in the hilus and inhibited the abnormal neurogenesis and astrogliosis in the hippocampus by inhibiting MAPK/ERK activity and c-Fos transcription. Celecoxib also up-regulated the expression of GABAA receptors. NS-398 （N-2-cyclohexyloxy-4-nitrophenyl-methanesulfonamide）, another COX-2 inhibitor, enhanced the frequency and decay time of mIPSCs. Conclusion： The COX-2 inhibitor celecoxib decreased neuronal excitability and prevented epileptogenesis in pilocarpine-induced status epilepticus rats. Celecoxib regulates synaptic reorganization by inhibiting astrogliosis and ectopic neurogenesis by attenuating MAPK/ERK signal activity, mediated by a GABAergic mechanism.

A Highly Efficient Catalyst FeCl3 in the Synthesis of α-Amino Phosphonates via Three-component Reactions

Three-component reactions of aldehydes, amines, and diethyl phosphite catalyzed by FeCl3 in EtOH or under solvent-free and mild conditions afforded the corresponding α-amino phosphonates in excellent yields.

Electrochemical synthesis of 3-azido-indolines from amino-azidation of alkenes

An electrochemical amino-azidation of 2-aminostyre ne with sodium azide(NaN3)was developed,which can be carried out smoothly in water under metal-free condition,affording a series of 3-azido indolines with high yields.

SmI_2-promoted imino-Reformatsky reaction for facile synthesis of enantioenriched β-amino acid esters

A facile and efficient method for the stereoselective synthesis of β-amino acid esters via SmI2-promoted imino-Reformatsky reaction is described.Asymmetric addition of tert-butyl bromoacetate to N-tert-butanesulfinyl aldimines afforded β-amino acid esters in moderate to high yields with excellent diastereoselectivities.The synthetic utilities of the tert-butyl β-amino acid esters were expanded by the preparation of β-lactams and 3-aminoindan-1-ones derivatives.

Synthesis and Microbial Studies of New Pyridine Derivatives-Ill

2-Amino substituted benzothiazole 4a--4I and p-acetamidobenzenesulfonyl chloride 2 were used to prepare 2-（p-aminophenylsulfonamido） substituted benzothiazole 6a--6I using mixture of pyridine and acetic anhydride which formed an electrophilic complex （N-acetyl pyridinium） to facilitate condensation to give desired product by removal of HC1. 2-{p-[（3-Carboxypyrid-2-y1）amino]phenylsulfonamido}benzothiazoles 8a--81 were synthesized from 2-chloropyridine-3-carboxylic acid 7 and 6a--6I in 2-ethoxy ethanol using Cu-powder and K2CO3. Acid chlorides 9a--91 were condensed with 2-hydroxyethyl piperazine 10 and 2,3-dichloropiperazine 11 for amide deriva- tives 2-（p-（（3-（4-（2-hydroxyethy1）piperazin-1-ylcarbonyl）pyrid-2-y1）amino）phenylsulfonamido）benzothiazoes 12a -121 and 2-{p-[3-（2,3-dichloropiperazin-l-ylcarbonyl）pyrid-2-ylamino]phenylsulfonamido}benzothiazoles 13a- 131 respectively. The structures of the new compounds have been established on the basis of their chemical analysis and spectral data （IR, 1↑H NMR and mass）. All the compounds have been screened for their antibacterial and antifungal activities.

Super-sensitive bifunctional nanoprobe: Self-assembly of peptide-driven nanoparticles demonstrating tumor fluorescence imaging and therapy

The development of nanomedicine has recently achieved several breakthroughs in the field of cancer treatment;however,biocompatibility and targeted penetration of these nanomaterials remain as limitations,which lead to serious side effects and significantly narrow the scope of their application.The self-assembly of intermediate filaments with arginine-glycine-aspartate(RGD)peptide(RGDIFP)was triggered by the hydrophobic cationic molecule 7-amino actinomycin D(7-AAD)to synthesize a bifunctional nanoparticle that could serve as a fluorescent imaging probe to visualize tumor treatment.The designed RGD-IFP peptide possessed the ability to encapsulate 7-AAD molecules through the formation of hydrogen bonds and hydrophobic interactions by a one-step method.This fluorescent nanoprobe with RGD peptide could be targeted for delivery into tumor cells and released in acidic environments such as endosomes/lysosomes,ultimately inducing cytotoxicity by arresting tumor cell cycling with inserted DNA.It is noteworthy that the RGD-IFP/7-AAD nanoprobe tail-vein injection approach demonstrated not only high tumor-targeted imaging potential,but also potent antitumor therapeutic effects in vivo.The proposed strategy may be used in peptide-driven bifunctional nanoparticles for precise imaging and cancer therapy.