Novel synthesis of 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde:A key intermediate of Losartan

A novel method for synthesis of 2-butyl-5 -chloro-3H-imidazole-4-carbaldehyde 2, a key intermediate of Losartan was reported. The compound 2 was synthesized from starting material dimethyl malonate 6 and n-valeronitrile 8 by six steps with an overall yield of 40%. The key step including the reaction of compound 5 with POCl3/DMF followed by hydrolysis to give compound 2 with the yield of 68%.

Coupling Reaction of 4-Chloro-7-H-Pyrrolo[2,3-d]Pyrimidine with 2,3,5-Tri-O-Acetyl-b-D-Ribofuranosyl Chloride

Coupling reaction of 4-chloro-7-H-pyrrolo[2,3-d]pyrimidine with 2,3,5-tri-O-acetyl -β-D-ribofuranosyl chloride under the basic condition was investigated. An abnormal coupling reaction, in which the heterocyclic base attacked at the carbon of 1,2-O-methylidene moiety instead of anomeric carbon of ribose was observed and the structure of products 5a, 5b were identified by NMR and X-Ray diffraction.

Resolution of RS-3-chloro-2-oxy-propyltrimethylammonium-chloride and Crystal Structure Studies on Its R,R-tartrate

RS-3-chloro-2-oxy-propyltrimethylammonium-chloride 1, an important inter- mediate of carnitine and acetylcholine, has been synthesized and resolved by using R,R-tartric acid. Di-(S-3-chloro-2-oxy-propyltrimethylammonium)-R,R-tartrate 2, with optical purity of 81.76%, has been obtained. Compound 2 was characterized by IR spectroscopy, MS, NMR and X-ray diffrac- tion, and it crystallizes in orthorhombic, space group P212121, absolute structure parameter 0.56(8), with cell parameters a = 8.323(2), b = 10.203(2), c = 26.178(5) ? C16H34Cl2N2O8, Mr = 453.272, V = 2223.0(8) ?, Z = 4, Dc = 1.354 g/cm3, m = 0.335 mm-1, F(000) = 968, R = 0.0534 and wR = 0.1274 for 4376 observed reflections (I > 2s(I)). The lattice is composed of two S-3-chloro- 2-oxy-propyltrimethylammonium cations and one R,R-tartrate dianion which are arranged in separate stacks linked via hydrogen bonds.

Synthesis,Crystal Structure and Anti-tumor Activity of 2-(2-Chloro-4-nitrophenyl)-4-(4-chlorophenyl)-3a,4-diethoxy-2,3,3a,4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole

The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was characterized by IR, MS, ^1H NMR, ^13C NMR, ^31p NMR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1^-, a = 9.1549（3）, b = 10.7168（4）, c = 17.6272（6）A, α = 102.9363（12）, β = 90.2713（9）, γ = 117.4265（10）°, V= 1484.41（9）A^3, Z= 2,μ（MoKa） = 0.323, F（000） = 658, Z= 2, De= 1.417 g/cm^3, the final R = 0.0687 and wR = 0.2066 for 4943 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the diazaphospholine ring is almost planar and the two ethoxy groups bonded on the 3a- and 4-positions are in trans configurations. Its antiproliferative activity was also tested in vitro against four human tumor cell lines.

(Z)-N-(3-(2-Chloro-4-nitrophenyl)-4-methylthiazol-2(3H)-ylidene) Pivalamide: Synthesis and Crystal Structure

Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.

Crystal Structure and Biological Activities of (R)-N′-[2-(4-Methoxy-6-chloro)-pyrimidinyl]-N-[3-methyl-2-(4-chlorophenyl)butyryl]-urea

The title compound （R）-N′-[2-（4-methoxy-6-chloro）-pyrimidyl]-N-[3-methyl-2-（4- chlorophenyl）butyryl]-urea has been synthesized, and its crystal structure and biological behaviors were studied. Crystallographic data： C17H18C12N4O3, Mr = 397.25, monoclinic, space group P21/c, a = 12.331（2）, b = 14.025（3）, c = 23.085（5） A, β = 99.607（4）°, Z = 8, V = 3936.2（13） A3, Dc = 1.341 g/cm^3, F（000） = 1648, R = 0.0718, wR = 0.1585 and/t（MoKα） = 0.353 mm^-1. The preliminary biological tests showed that the title compound has definite insecticidal and fungicidal activities.

Asymmetric synthesis of syn-aryl-(2S,3R)-2-chloro-3-hydroxy esters via an engineered ketoreductase-catalyzed dynamic reductive kinetic resolution

We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed evolution.The hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.

Asymmetric Reduction of 2-Chloro-3-oxo Esters by Transfer Hydrogenation

Asymmetric reduction of 2-chloro-3-oxo esters was achieved by catalytic transfer hydrogenation using [RuCl2（p-cymene）]（S,S）-TsDPEN as the chiral catalyst and HCOOH-Et3N as the hydrogen source. Moderate to good yields （up to 85%） and good enantioselectivities （up to 98% ee） were obtained.

An approach to synthesis of(Z)-2-chloro-1,3-diarylpropen-1-ones by Vilsmeier reagent(bis-(trichloromethyl)carbonate/DMF)

A series of（Z）-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis（trichloromethyl） carbonate（BTC, triphosgene） and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.

Approach to synthesis of novel chiral 3-chloro-2(5H)- furanone and its application in asymmetric reactions

The synthetic method of the novel chiral synthon, 5-/-menthyloxy-3-chloro-2-(5H)-furanone 5a and its application in asymmetric reactions were investigated. 5a is easily obtained in highly optical purity, and acts as a stable acceptor of Michael addition with oxygen nucleophiles in tandem double Michael addition / internal nucieophilic substitution to offer the spiro-cyclopropane derivative containing four stereogenic centers 8, which it is difficult to obtain by routine methods. The synthetic methods for 5a and 8 are reported in detail and the new compounds are identified on the basis of their analytical data and spectroscopic data, such as UV, IR, H NMR,13 C NMR, MS and elementary analysis. The absolute configuration of the interesting spiro-cyclopropanes, spiro [1-chloro-4-(/-menthyloxy)-5-oxo-6-oxa-biscyclo[3.1.0]hexane-2,3i(4’-/-menthyloxy-5’-/-menthyloxy- butyrolactone)] 8 was established by X-ray crystallography. This result can provide important synthetic strategy in synthesis of some complex

A highly enantioselective synthesis of 5- (ι-menthyloxy) -4-substituted-3-chloro-2(5H) -furanones

In this paper, stereocontrolled tandem Michael addition-elimination reaction of the novel chiral source, S-(ι-menthyloxy)-3,4-dichloro-2(5H)-furanone, with various thiols and amines has been investigated. A series of new enantiomerically pure compounds, 5-(ι-menthyloxy)-4-substituted-3-cnloro-2(5H)-furanones, were obtained in good yields with d. e.(?)98% under mild conditions.

A New Hemiterpene Derivative from Prinsepia utilis

A new hemiterpenoid, （＋）-（2R,3S）-2-chloro-3-hydroxy-3-methyl-T-buty-rolactone was isolatexi from the leaves of Prinsepia utilis Royle. Its structure was clucidatexi by spectroscopic methods and X-ray crystallographic analysis.

马来酸氟吡汀的合成

通过对马来酸氟吡汀的合成研究,确定并打通了马来酸氟吡汀的合成路线,该工艺条件与其他路线比较,具有起始原料易得、产品收率高、操作简便等优点。即以2-氨基-3-硝基-6-氯吡啶为原料与对氟苄胺反应,然后氢化还原后,滤液进行酰化反应得到氟吡汀碱,经五步反应得到马来酸氟吡汀,结构经1H-NMR确认,总收率77%,含量大于99.9%,产品质量符合2010版药典要求。

Mild and Efficient Synthesis of 1-（6-Chloroquinoxalin-2-yl）-2- [4-（trifluoromethyl）-2,6-dinitrophenyl] Hydrazine Derivatives by Microwave Irradiation

Some 1-（6-chloroquinoxalin-2-yl）-2-[4-（trifluoromethyl）-2,6-dinitrophenyl] hydrazine derivatives have been synthesized via both conventional and microwave assisted organic synthesis（MAOS） methods. The MAOS method is more effective on synthesizing these compounds than the conventional method in regard to the higher chemical yields of products（76%-98%） and the shorter reaction time（1-15 min）.

Fast ethylamine gas sensing based on intermolecular charge-transfer complexation

We have investigated the fast ethylamine gas sensing of 2-chloro-3,5-dinitrobenzotrifluoride（CDBF） loaded poly（acrylonitrile） nanofiber based on an intermolecular charge-transfer complexation.Reversible response and recovery were achieved using alternating gas exposure.This system shows a fast ethylamine gas sensing within 0.4 s.