Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro[2,3-d]pyrimidin-4（3H）-one

The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4（3H）-one （C16H18N2O3, Mr = 286.32） has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167（14）, b = 13.113（1）, c = 8.378（1） A, β = 98.992（2）^o, V = 1488.4（3） A^3, Z = 4, Dc = 1.278, F（000） = 608, μ = 0.089 mm^-1, MoKa radiation （2 = 0.71073）, R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar.     

An efficient route for synthesis of 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4(3H)-one

The carbodiimide 2,obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates,reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4(3H)-ones 4 and 5.The formation mechanism of the title compounds has been investigated.     

2-烷(芳)氧基苯并呋喃并[3,2-d]嘧啶-4(3H)-酮衍生物的合成及杀菌活性

应用膦亚胺3与芳基异氰酸酯的氮杂Wittig反应, 生成碳二亚胺4, 4再分别与酚、醇作用, 在碳酸钾或醇钠催化下关环, 以72%～88%的产率合成了2-烷(芳)氧基取代-苯并呋喃并[3,2-d]嘧啶-4(3H)-酮衍生物5和6, 其结构经IR, 1H NMR, MS和元素分析证实. 初步生物活性测试表明该类化合物表现出温和的杀菌活性. 如5f在50 mg/L浓度时, 对黄瓜灰霉菌的抑制率为55%.     

Synthesis and Crystal Structure of 1-（4-Fluorophenyl）-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H）-one

The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5) ,β = 99.364(2) °,V = 4332.58(18) 3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I > 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.     

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, C_(46)H_(68)N_6O_(10), 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) ?, 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/cm~3, 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.     

Synthesis and Crystal Structure of 2-(4''-Methylphenoxy)-5,8,9-trimethyl-3-phenyl Thieno[3'',2'':5,6]pyrido[4,3-d]pyrimidin-4-(3H)-one Hydrochloride

The title compound 2-(4′-methylphenoxy)-5,8,9-trimethyl-3-phenyl thieno[3′,2′:5,6]pyrido[4,3-d]pyrimidin-4(3H)-one hydrochloride (C26H23Cl4N3O2S, Mr = 583.33) has been deter- mined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 14.8442(11), b = 11.5131(8), c = 17.2010(13) (A), β = 113.7250(10)o, V = 2691.3(3) (A)3, Z = 4, Dc = 1.440 g/cm3, S = 1.094, μ = 0.547 mm-1, F(000) = 1200, the final R = 0.0571 and wR = 0.1458. X-ray analysis reveals that the title compound combines with a molecule of dichloromethane by an intramolecular hydrogen bond. The thienopyridine ring is almost coplanar, and the dihedral angle between the thiophene plane and the pyridine plane is 0.6o.     

[1]Benzothienopyrimidines. II. Study of the electrophilic substitutions of [1]benzothieno[3,2-d]pyrimidine and [1]benzothieno[3,2-d]pyrimidin-4-(3H)one

The nitration and bromination of both [1]benzothieno[3,2-d]pyrimidin-4(3H)one ( 1 ) and [1]benzothieno-[3,2-d]pyrimidine ( 2 ) has been studied. Nitration of 1 at ?30° afforded a mixture of 8-nitro[1]benzothieno-[3,2-d]pyrimidin-4(3H)one ( 7b ) (70%) and 6-nitro[1]benzothieno[3,2-d]pyrimidin-4(3H)one ( 7a ) (30%). However when the nitration was carried out at 60°, the 6,8-dinitro derivative 8 was the result. On the contrary, the nitration of 2 at ?30° gave a single nitration product, 8-nitro[1]benzothieno[3,2-d]pyrimidine ( 11 ). The bromination of both 1 and 2 gave the corresponding 8-bromo derivatives 10 and 13 . Assignment of structure of all the products was based on ir and nmr spectral studies and on unequivocal syntheses.     

Crystal structure of 2-(6-chloro-4-P-tolylamino)pyrido[3,2-d]pyrimidin-1-ium-1-yl)acetate oxonium bromide

The crystals of 2-(6-chloro-4-(p-tolylamino)pyrido[3,2-d]pyrimidin-1-ium-1-yl)acetate (zwitterionic form) oxonium bromide, C₁₆H₁₃ClN₄O₂·Br⁻·H₃O⁺ (I) were prepared and studied by single-crystal X-ray diffraction method. The compound crystallizes in the triclinic space group P-1 with a = 8.3121(8) ?, b = 9.3885(8) ?, c = 13.2903(12)?, α = 106.788(2)°, β = 95.204(3)°, γ = 110.871(2)°, V = 905.81(14) ?³, Z = 2; final R = 0.053, wR2 = 0.150. It is interesting that methylene C in the BrCH₂COOH molecule binds to the N1 of the pyrimidine ring. In the crystal studied, two neighboring organic molecules are connected by hydrogen bonds through carboxylate oxygen, oxonium and bromide ions to form a dimer.     

Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9 (3H)-one derivatives. I.

A series of 6-substituted [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives 4a--z were synthesized from 5-substituted 1,3,4-thiadiazol-2-amines 5 by the following consecutive reactions: pyrimidine ring closure with bis(2,4,6-trichlorophenyl) malonate, nitration, chlorination, amination, hydrogenation and diazotization. The structure of 4 was confirmed by an alternate synthesis of 4, involving reaction of 5-substituted 2-azido-1,3,4-thiadiazole 13 with ethyl cyanoacetate, followed by the Dimroth rearrangement and ring closure. The antiallergic activities (anti-passive peritoneal anaphylaxis, anti-passive cutaneous anaphylaxis and anti-slow reacting substance of anaphylaxis activities) of the products were evaluated.     

Zn(OAc)2 catalyzed microwave irradiated synthesis of substituted thieno[2,3-d]pyrimidin-4(3H)-one

Different Lewis acids were screened to catalyze the reaction of 2-amino-thiophene-3-carboxylate, orthoformate and aryl amine to form 2-substituted thieno[2,3-d]pyrimidin-4(3H)-one. Zn(OAc)₂ was demonstrated to efficiently catalyze the reaction. 20 substituted thieno[2,3-d]pyrimidines were synthesized by adding 0.5% mol Zn(OAc)₂ as catalyst under microwave irradiation.     

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)?,β = 93.806(5)o,V = 2207.1(11) ?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 ?),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) ?,β = 93.047(7)o,V = 1122.1(9) ?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 ?),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.     

Synthesis and Structure of 6-(4- Fluorobenzylamino)-3-methylthio-1,5- diphenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

1 INTRODUCTION It was reported that the pyrazolopyrimidinone derivatives play a very important role in the bio- chemistry of living cell. Many potential drugs[1～3] and agrochemicals[4, 5] have been modeled on the compound, and the study on derivatives …     

A facile synthesis of 3-substituted 2-cyanoquinazolin-4(3H)-ones and 3-alkyl-2-cyanothieno[3,2-d]pyrimidin-4(3H)-ones via 1,2,3-dithiazoles

The reaction of methyl anthranilate with 4,5-dichloro-1,2,3-dithiazolium chloride (Appel's salt) in the presence of pyridine (2 equivalents) in dichloromethane at room temperature gave methyl N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)anthranilate ( 3a ) (50% yield), which reacted with sterically less hindered primary alkylamines to give directly 3-alkyl-2-cyanoquinazolin-4(3H)-ones 5 in moderate to good yields. With tert-butylamine, N-(2-methoxycarbonylphenyl)iminocyanomethyl N-(tert-butyl) disulfide 7 and methyl 2-(N-cyanothioformamido)anthranilate ( 8 ) were isolated in 33% and 59% yields, respectively. The cyano group of quinazoline 5a (R = CH₃) is readily displaced by various nucleophiles to give 2-substituted quinazolinones 11–19 , which indicates that compounds 5 can be utilized as starting materials for the synthesis of new 2-substituted quinazolines. Similarly 3-alkyl-2-cyanomieno[3,2,-d]pyrimidin-4(3H)-ones 22 were prepared from methyl 3-[N-(4-chloro-5H-1,2,3-dimiazol-5-ylidene)]-2-thiophencarboxylate ( 21 ) in moderate to good yields.     

Crystal structure of trans(3R,2aS)-(-)-3-phenyl-hexahydro-oxazolo[3,2-a]pyridin-5-one.

Chiral, non-racemic hexahydro-oxazolo[3,2-a]pyridin-5-ones are strategic starting materials for the asymmetric synthesis of alkaloids, via the stereoselective C-C bond formation at the position a to the nitrogen atom. The stereoselectivity of this key step is mainly driven by the geometry of the fused rings of the oxazolopyridine moiety. In this work, the synthesis and X-ray structure of trans(3R,2aS)-(-)-3-phenyl-hexahydro-oxazolo[3,2-a]pyridin-5-one is reported.     

Synthesis and Crystal Structure of 2-Amino-3-ethoxycarbonyl-4-（4-chlorophenyl）-4H, 5H-pyrano-[3,2-c]-benzopyran-5-one

1 INTRODUCTION The coumarins constitute an important class of bioactive natural products[1]. They have been found to possess diverse biological properties including antimicrobial, insecticidal, estrogenic, anticoagulant and antithrombotic activities. Som…     

Synthesis of pyrido[2,3-d]pyrimidin-4-one derivatives

This paper describes one-pot synthesis of 5H-[1,3]thiazolo[3,2-a]pyrido[3,2-e]pyrimidin-5-one 4 , 5H-dipyri-do[1,2-a:3′,2′-e]pyrimidin-5-one 10 and 5H-pyrido[3,2-e]pyrimido[1,2-a]pyrimidin-5-one 15 and some of their derivatives, starting with 2-chloro-3-pyridine carboxilic acid 1. Compounds 4 and 10 reacted with phosphorus pentasulfide to give the respective 5-thione analogues, 5 from 4 and 11 from 10 . Boiling the 5-thione derivatives with hydrazine hydrate, the respective 5-hydrazono derivatives 6 from 5 and 12 from 11 were obtained. The 5-acetyl hydrazono, 7 , and the 5-isopropylidenehydrazono, 8 , derivatives were also prepared from 6 , and the 5-propionylhydrazono derivatives, 13 , from 12 . Compound 4 reacted with hydrazine to give an adduct with two molecules of hydrazine and the probable structure 16 . Treating this adduct with acetone a monohydrazone 17 was obtained. Boiling a suspension of this adduct in DMF, it gave 6,10-dihydro-6H-pyrido[3′,2′:5,6]pyrimido[2,1-c][1,2,4]triazin-5-one 20 .