Microwave irradiation: Novel and facile methods for the synthesis of new pyrimidinones

We describe here a rapid process for the preparation of new 9-chloromethyl-12-aryl-10,12-dihydrobenzo[5,6]chromeno[2,3-d]pyrimidin-11-ones 5a-d and 10-chloromethyl-7-aryl-7,9-dihydrobenzo[7,8]chromeno[2,3-d]pyrimidin-8-ones 6a-d by two different methods utilizing microwave irradiation. This methodology provides better yields（72%–80%） and high purity of the title compounds.

Rapid and mild synthesis of quinazolinones and chromeno[d]pyrimidinones using nanocrystalline copper(Ⅰ)iodide under solvent-free conditions

This paper describes a very simple, efficient synthesis of quinazolinones and chromeno[d]pyrimidinones from the reaction of aryl aldehydes, urea/thiourea and active methylene compounds（dimedone/4-hydroxycoumarin） using nano-sized CuI particles under solvent-free conditions. The highlights of this new method are based on using an effective and recyclable catalyst, affording high yields of products,mild reaction conditions, facile work-up and purification.

A New Discovery towards Novel Skeleton of Benzimidazole-Conjugated Pyrimidinones as Unique Effective Antibacterial Agents

A class of new potential antibacterial agents with distinctive pyrimidinone benzimidazole skeleton was developed through nucleophilic substitution and Biginelli reaction starting from urea,ethyl 4-chloroacetoacetate and various aldehydes.Some target molecules exhibited strong antibacterial activities,especially pyrimidinone benzimidazole hybrid 9e possessed the strongest inhibitory effects on the growth of E.faecalis and P.aeruginosa with a lower MIC value of 1μg/mL than norfloxacin.Moreover,compound 9e displayed strong antibiofilm capacity,low drug resistance and excellent biosafety toward human red blood cells.Further research revealed that compound 9e could disrupt membrane integrity and cause leakage of cellular components such as proteins and nucleic acids.Meanwhile,compound 9e could decrease lactate dehydrogenase activity,block cell metabolism and interact with DNA in an intercalation manner.

An efficient method for the synthesis of thieno[3',2':2,3]pyrido-[4,5-d]-thiazolo[3,2-a]pyrimidinones

An efficient method for the preparation of thieno[3＇,2＇：2,3]pyrido[4,5-d]thiazolo[3,2-a] pyrimidin-5-ones 5 is described. The key intermediate, 7-（3-amino-4-cyano-5-phenyl aminothieno-2-yl）-5H-thiazolo-[80_TD$IF]3,2-a]pyrimidin-5-one（3）, was synthesized from 7-chloromethyl-5H-thiazolo[3,2-a]pyrimidin-5-one（1）with potassium-（2,2-dicyano-1-phenylaminoethen-1-yl）thiolate（2） by Thorpe–Ziegler isomerization.Subsequent reaction of the intermediate amine with aromatic aldehydes via Pictet–Spengler reaction provided thieno-pyridine fused thiazolo[3,2-a]pyrimidines under p-Ts OH as catalyst in good yields.

Synthesis, Crystal Structure and Antitumor Activity of 3,3-(1,4-Phenylene)-bisfuro[3,2-d]pyrimidin-4(3H)-ones

3,3-(1,4-Phenylene)-bis(polysubstituted furo[3,2-d]pyrimidin-4(3 H)-ones 3 were synthesized from the starting material of functionalized iminophosphorane 1 by aza-Wittig reaction. All of the title compounds were characterized by 1H NMR, MS and elemental analysis. Meanwhile, the single crystal of compound 3 c, C46H68N6O10, was also obtained and determined by X-ray crystallography. Crystal data: triclinic, space group P1, a = 9.0017(3), b = 10.5908(4), c = 14.0116(5) A, α = 108.582(2)°, β = 94.296(1)°, γ = 105.059(2)°, V = 1204.40(7) ?3, Z = 1, F(000) = 466, Dc = 1.193 g/cm3, μ = 0.084 mm-1, R = 0.0998 and wR = 0.2146 for 4213 independent reflections(Rint = 0.0689) and 2796 observed ones(I > 2σ(I)). The in vitro antitumor activities of compounds 3 a^3 c were preliminarily evaluated by the standard MTT assay.

Efficient Synthesis,Crystal Structure and Antibacterial Activity of Two Novel Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives

Two new thieno[2,3-d]pyrimidin-4（3H）-one derivatives,C24H22 Cl N3O2S（5a） and C25H25N3O2S（5b）,have been synthesized via a tandem aza-Wittig reaction.This tandem reaction has many attractive aspects such as easily accessible and versatile starting materials,mild conditions and high yields.Both compounds have been characterized by elemental analysis,HR-MS,IR,NMR spectra and X-ray single-crystal diffraction.Compound 5a crystallizes in monoclinic,space group P21/c with a = 9.986（3）,b = 14.263（4）,c = 15.530（5）A,β = 93.806（5）o,V = 2207.1（11） A^3,Mr = 451.96,Z = 4,Dc = 1.360 g/cm3,F（000） = 944,μ = 0.294 mm-1,Mo Kα radiation（λ = 0.71073 A）,the final R = 0.0444 and w R = 0.1219 for 3407 observed reflections with I 〉 2σ（I）.Compound 5bcrystallizes in triclinic,space group P1 with a = 8.974（4）,b = 10.766（5）,c = 12.260（6） A,β = 93.047（7）o,V = 1122.1（9） A^3,Mr = 431.54,Z = 2,Dc = 1.277 g/cm3,F（000） = 456,μ = 0.170 mm-1,Mo Kα radiation（λ = 0.71073 A）,the final R = 0.0378 and w R = 0.1072 for 3806 observed reflections with I 〉 2σ（I）.The preliminary antibacterial activities of 5a and 5b were investigated.Compound 5a showed 71.3% and 79.2% in vitro inhibition against Fusarium oxysporium and Rhizoctonia solani,respectively.Compound 5b showed 75.3% in vitro inhibition against Rhizoctonia solani.

A Macroporous Cryogel with Enhanced Mechanical Properties for Osteochondral Regeneration In vivo

The dense networks of conventional hydrogel hinder the efficient cell penetration and thus tissue regeneration.In this study,a macroporous cryogel with excellent mechanical properties was designed and fabricated through cryogelation and crosslinking of methacrylated gelatin(Gel-MA)and gelatin grafted with 2-ureido-4[1H]-6-methyl-pyrimidinone(Gel-UPY).The successful modification of the two functional units on the side chain of gelatin was confirmed by ^(1)H-NMR and infrared spectroscopy.The macroporous structure of cryogel was verified by scanning electron microscopy and confocal microscopy.The compressive modulus of cryogel(110 kPa)was 2 magnitudes higher than that of the conventional hydrogel of the same chemical compositions(8 kPa).Both the hydrogel and cryogel exhibited excellent stress-recovery ability.The cryogel could well maintain the viability of chondrocytes and facilitated their migration into the scaffold interior.After being implanted into osteochondral defects in rabbits for 12 w,the Gel-MA/Gel-UPY cryogel better facilitated the regeneration of upper cartilage and subchondral bone compared to the conventional hydrogel.

Bronsted acidic ionic liquid [C_3SO_3HDoim]HSO_4 catalyzed one-pot three-component Biginelli-type reaction: An efficient and solvent-free synthesis of pyrimidinone derivatives and its mechanistic study

A series of Bronsted acidic ionic liquids（ILs） were prepared and used for Biginelli-type condensation reaction among aromatic aldehydes, urea or thiourea and cyclopentanone. Through this reaction, the synthesis of various pyrimidinones could be achieved. Of interest, it was found that the reaction was efficiently catalyzed by a novel, eco-friendly functionalized IL [C3SO3HDoim]HSO4, which could be reused for at least 7 times without significantly loss of catalytic activity. The reaction proceeded efficiently at 80℃ to afford the desired products in good yield（up to 96%）. In addition, a possible mechanism that accounted for the IL [C3SO3HDoim]HSO4-catalyzed reaction was proposed.

N-Heterocyclic Carbene-catalyzed Reactions of o-Aminonitriles with Carbonyl Compounds Approach to 2,3-Dihydroquinazolin-4(1H)-ones

A green,efficient and convenient N-heterocyclic carbene-catalyzed procedure for the synthesis of novel 2,3-dihydroquinazolin-4(1H)-one derivates via condensation of o-aminonitriles and various carbonyl compounds was described.