4-溴代苯酐的合成新方法

将4-硝基邻苯二甲酰亚甲胺（4-NPI）用铁粉还原为4-氨基邻苯二甲酰亚甲胺 ，再在氢氧化钠水溶液中水解成4-氨基邻苯二甲酸钠。4-氨基邻苯二甲酸钠在氢溴 酸中经Sandmeyer反应合成4-溴代苯酐。产品纯度高，是合成4-溴代苯酐的一个比较 理想的方法。     

Synthesis of 2-substituted-5-halo-2,3-dihydro-4(H)-pyrimidin-4-ones and their derivatization utilizing the Sonogashira coupling reaction in the enantioselective synthesis of alpha-substituted beta-amino acids

A convenient, one-pot procedure for the synthesis of 1-benzoyl-2(S)-substituted-5-iodo-2,3-dihydro-4(H)-pyrimidin-4-ones by tandem decarboxylation/beta-iodination of the corresponding 6-carboxy-perhydropyrimidin-4-ones was developed. In addition, several 1-benzoyl-2(S)-substituted-5-bromo-2,3-dihydro-4(H)-pyrimidin-4-ones were readily prepared by bromination of 1-benzoyl-2(S)-substituted-2,3-dihydro-4(H)-pyrimidin-4-ones. Subsequently, Sonogashira coupling of the halogenated heterocyclic enones with various terminal alkynes produced 1-benzoyl-2(S)-isopropyl-5-alkynyl-2,3-dihydro-4(H)-pyrimidin-4-ones in good yields. Hydrogenation of the unsaturated C-C moieties in the Sonogashira products followed by acid hydrolysis afforded highly enantioenriched alpha-substituted beta-amino acids.     

A novel cyclodimerization of 3-methyl-3-butenenitrile. An efficient synthesis of 4-cyanoisophorone

Dimerization of 3-methyl-3-butenenitrile (1) by lithium dialkylamide gave selectively 3,5,5-trimethyl-1-amino-4-cyanocyclohexa-1,3-diene (2), which was easily hydrolyzed by aqueous acid to afford 4-cyanoisophorone (3,5,5-trimethyl-4-cyano-cyclohex-2-enone) (3) quantitatively.     

Synthesis of 4-aryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b][1,4]-diazepin-6-ones from 4,5-diamino-1H-pyrimidin-6-ones and 1-aryl-3-(dimethylamino)-1-propanones

The reaction of 1-aryl-3-(dimethylamino)-1-propanones 1 with one equivalent of 4,5-diamino-1H-pyrimidin-6-ones 2 , in acidic medium, leads to the formation of 4-aryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b]-[1,4]diazepin-6-ones 3 . The structure elucidation of the products is based on detail nmr analysis of experiments such as ¹³C, ¹H and DEPT including selective ¹³C{¹H} decoupling experiments.     

Synthesis of the metabolites of oxapadol,a new non-narcotic analgesic agent

Different metabolites (2-7) of oxapadol 1 were carried out from 3 by known methods. Their acidic hydrolysis provided compounds 4 in which the dioxolane moiety was opened. The reaction of glycerol with compounds 3 gave the dioxolane derivatives 5 which have a hydroxymethyl group and which (R = H) gave by oxidation the carboxylic acid 7. From 3 (R = H), the hydroxy acid 6 has been also prepared.     

Synthesis of Some New Benzopyranopyrimidin-2-Thiol Derivatives

Reaction of 2-mercapto-4-hydroxy-5H-[1]-benzopyrano-[4,3- d ]-pyrimidin-5-one ( 3 ) with phenyl isothiocyanate and methyl acrylate yielded the corresponding 2-(substituted)thio-4-hydroxy-5H-[1]-benzopyrano-[4,3- d ]-pyrimidin-5-ones ( 4 , 5 ). Hydrolysis and hydrazinolysis of 5 gave acid derivative 6 , and hydrazone 7 . Treatment of hydrazone 7 with ethyl acetoacetate, diethyl malonate, and phenyl isothiocyanate yielded the corresponding 2-(substituted)thio-4-hydroxy-5H-[1]-benzopyrano- [4,3- d ]-pyrimidin-5-ones ( 8 , 9 , and 11 ). Cyclization of 11 with 2 N NaOH led to 12 .     

The synthesis and determination of acidic ionization constants of certain 5-substituted 2-aminopyrrolo[2,3-d]pyrimidin-4-ones and methylated analogs

The acidic ionization constants were determined for a series of 5-substituted 2-aminopyrrolo[2,3-d]-pyrimidin-4-ones and N -3- and N -7-methylated analogs thereof. The syntheses of the methylated analogs are also described.     

Zinc hydrazides and alkoxyhydrazides: organometallic compounds with novel Zn4N8, Zn4N6O and Zn4N4O2 cage structures

Tetrameric [{RZn(NHNMe2)}4] (R = Me, Et), the first organometallic zinc hydrazides to be described, have been prepared by alkane elimination from dialkylzinc solutions and N,N-dimethylhydrazine. They were characterised by 1H and 13C NMR and IR spectroscopy, mass spectrometry, elemental analysis and X-ray crystallography. The compounds form asymmetric aggregates containing the novel Zn4N8 core; tetrahedra of Zn atoms bear the alkyl groups at Zn, with the triangular faces bridged by NHNMe2 substituents. The NH groups are connected to two Zn atoms, and the NMe2 groups to one. Hydrolysis of the compounds with water gives [(RZn)4(OH)(NHNMe2)3] as products, which also were characterised as described above. Higher yields of these hydroxo clusters were achieved in one-pot syntheses by reaction of dialkylzinc solutions with mixtures of N,N-dimethylhydrazine and water. They contain Zn4N6O cages, in which one hydroxide in the tetrameric hydrazides described above replaces one NHNMe2 group. Similar products can be prepared with alkoxy instead of hydroxy groups, in analogous one-pot syntheses with alcohols. Alcoholysis of [EtZn(NHNMe2)]4 with methanol or ethanol gave zinc trishydrazide monoalkoxides, [(EtZn)4(OR)(NHNMe2)3] (R = Me, Et), which have constitutions analogous to the monohydroxides. The organozinc bishydrazide bisalkoxides [(MeZn)4(NHNMe2)2(OEt)2] and [(EtZn)4(NHNMe2)2(OEt)2] were obtained in one-pot reactions from dialkylzinc solutions with mixtures of the hydrazine and alcohol, and their crystal structures, confirmed by spectroscopic methods in solution, show an unsymmetrical aggregation with the novel Zn4N4O2 cage structure.     

Synthesis, reactions and antimicrobial activities of 8-ethoxycoumarin derivatives

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl(3) gave b-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH(2))(2)·H(2)O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a-c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.     

Insights into regioselective oxy (-O-) and imino (-NH-) group insertions of 3-nortricyclanone.

Lactam 4-azatricyclo[3.2.1.0(2,7)]octan-3-one (16a) was proven to be formed in a previously reported reaction that claimed production of lactam 3-azatricyclo[3.2.1.0(2,7)]octan-4-one (17a). In a related reaction, bicyclo[3.1.0]hex-2-ene-endo-6-carbonitrile (15), lactam (16a), and novel hydroxycarbonitriles 19-21 were selectively formed when 3-nortricyclanone (1) was treated with aqueous hydroxylamine-O-sulfonic acid (HOSA). Since nitrile 15 neither hydrolyzed nor underwent intramolecular Ritter reaction under these conditions, mechanisms involving Beckmann rearrangement of 3 to nitrilium ion 9 (normal) and Beckmann fragmentation of 3 to cation 8 (abnormal) were investigated using semiempirical calculations. When alkaline HOSA was employed, lactams 16a and 17a were formed in a 1:2 ratio, perhaps via oxaziridine 6a. A similar selectivity was observed using an NH(3)/NaOCl reagent solution, which afforded lactone 4-oxatricyclo[3.2.1.0(2,7)]octan-3-one (16b) in addition to both lactams. Consequently, the Baeyer-Villiger oxidation of 1 with NaOCl gave 16b exclusively. Finally, the Schmidt reaction of ketone 1 gave only the lactam 17a, via cyclopropyl migration, and the same fragmentation products obtained from the acidic HOSA reaction. Migration selectivities are rationalized in terms of nucleofugacity, electronic effects, cyclopropyl regulation, and MO theory.     

Synthesis of 4-methoxy-2,3,5-trimethylpyridine: a specific building block for compounds with gastric-acid inhibiting activity

A new synthesis of 4-methoxy-2,3,5-trimethylpyridine (2), an important building block for the preparation of gastric-acid inhibiting compounds, is described. Condensation of ethyl 3-amino-2-methyl-2-butenoate (3) and diethyl 2-methylmalonate (4) gives 4-hydroxy-3,5,6-trimethyl-2(1H)-pyridone 5. Reaction of 5 with phosphoryl chloride affords 2,4-dichloro-3,5,6-trimethylpyridine (9a), which, upon hydrogenolysis with palladium on charcoal, gives 2,3,5-trimethylpyridine (10). However, selective hydrogenolysis in acidic solution yields 4-chloro-2-3-5-trimethylpyridine (11). Substitution of the chlorine in 11 with methoxide ion gives 4-methoxy-2,3,5-trimethylpyridine (2), which can be oxidized to the corresponding N-oxide (13). This constitutes a new and efficient route to compound 2 in an overall yield of 43%.     

Research on pyranes,their analogs,and related compounds

The action of methanol on methyl 4, 4-dichlorochromene-2-carboxylate (A) gives a 2-substitution product I, readily hydrolyzed in acid solution to a 2-hydroxy derivative C, which undergoes an allylic rearrangement to an ester of chromane-2-carboxylic acid B. Hydrogenation of compound I gives 2-methoxy-2-carbomethoxychromane (II), which is caused to undergo some chemical reactions.For Part XXIII see [4]     

膦、胂叶立德的化学与应用 XII. 对硝基苯基亚甲基三苯基膦、胂与2-全氟炔酸甲酯的反应以及(Z)3-全氟烷基 4-对硝基苯基-3-丁烯酸甲酯的立体专一性合成

溴化对硝基苄基三苯基 (1a)、 (1b)在碳酸钾存在下与2-全氟炔酸甲酯(2)在常温下反应, 生成加合物3(当M=As时)或3和4的混合物(当M=P时), 其中3的含量随反应温度升高而增加, 当反应温度为90℃时, 产物全部为3。4c加热时转化为3c。膦加合物3或4在甲醇-水中于封管内150℃加热, 发生P-C键断裂。两者都立体专一性地生成(Z)3-全氟烷基-4-对硝基苯基-3-丁烯酸甲酯(5)。胂加合物3在甲醇-水中回流, 发生As-C键断裂, 生成(Z)-5。对水解机理进行了研究。     

Furopyridines. VI. Preparation and reactions of 2- and 3-substituted furo[2,3-b]pyridines

This paper describes the synthesis and chemical properties of some 2- and 3-substituted furo[2,3-b]pyridines. Reaction of ethyl 2-chloronicotinate 1 with sodium ethoxycarbonylmethoxide or 1-ethoxycarbonyl-1-ethoxide gave β-keto ester 2 or ketone 5 , respectively. Ketonic hydrolysis of 2 afforded ketone 3, from which furo[2,3-b]pyridine 4 was obtained by the method of Sliwa. While, 2-methyl derivative 7 was prepared from 5 by reduction, O-acetylation and the subsequent pyrolysis. Reaction of ketone 3 with methyllithium gave tertiary alcohol 8 which was O-acetylated and pyrolyzed to give 3-methyl derivative 9 . Formylation of 4 , via lithio intermediate, with DMF yielded 2-formyl derivative 10 , from which 7 , was obtained by Wolff-Kishner reduction. Dehydration of the oxime 11 of 10 gave 2-cyano derivative 12 , which was hydrolyzed to give 2-carboxylic acid 13 . Reaction of 3-bromo compound 14 with copper(I) cyanide gave 3-cyano derivative 15 . Alkaline hydrolysis of 15 afforded compound 16 and 17 , while acidic hydrolysis gave carboxamide 18 . Reduction of 15 with DIBAL-H afforded 3-formyl derivative 19 . Wolff-Kishner reduction of 19 gave no reduction product 9 but hydrazone 20 . Reduction of tosylhydrazone 21 with sodium borohydride in methanol afforded 3-methoxymethylfuro[2,3-b]pyridine 22 .     

Self-assembled hemicapsules with inherent functionalities: modeling of a supramolecular electrostatic self-assembly

An approach to functional self-assembled hemicapsules is described consisting of the use of multivalent (valency > or = 4) and divalent components, the functional groups of which have a relatively weak binding affinity. Electrostatic self-assembly of tetrakis(pyridiniummethyl)cavitand hemispheres (H) and doubly charged anions (A) in polar media gives rise to an equilibrium mixture that consists, as detected with ESI-MS, of hemicapsule H2A3, capsule H2A4, and other ion-pair associates. Fitting 1H NMR data with a model that includes (hemi)capsules and ion-pair associates gave an effective molarity (EM) for the intramolecular assembly of the host (H) with sulfate (A) of 0.19 +/- 0.02 M and binding constants of the functional [2 + 3] hemicapsules H2A3 and the [2 + 4] capsules H(2)A(4) in methanol of 3.25 x 10(12) M(-4) and 3.45 x 10(15) M(-5), respectively. A substantial amount of the functional [2 + 3] hemicapsules H2A3 with respect to [2 + 4] capsules H2A4 is present in solution, with ratios of H2A3 to H2A4 of 5.67-0.43 in the studied concentration range (0.1-25 mM of [H]tot). The [2 + 3] hemicapsules H2A3 built with sulfate linkers incorporate guests between the closely positioned pyridinium planes.     

Photo- and thermal elimination of nitrogen from 4-phenyl- and 4,5-diphenyl-1,2,3-triazole

Phenylacetonitrile ( 2 ) (32%) and small amounts of benzyl methyl ether ( 3 ), benzonitrile ( 5 ) and methyl benzoate ( 6 ) were produced by irradiation of either 4-phenyl-1,2,3-triazole ( 1 ) or 4-phenyl-5-deutero-1,2,3-triazole ( 7 ) in methanol at 254 nm. In methylene chloride, irradiation of 1 produced 2 (15%) and small amounts of 3,6-diphenyl-1,2,4,5-tetrazine ( 8 ). Irradiation of 4,5-diphenyl-1,2,3-triazole ( 9 ) in methanol gave 2,4,5-triphenylimidazole ( 11 ) (4%) and trace amounts of diphenylacetonitrile ( 10 ), benzamide ( 12 ), and compounds 3 , 5 , and 6 . Irradiation of 2,3-diphenyl-2H-azirine ( 13 ) in methanol gave small amounts of 3 , benzaldehyde ( 4 ), and compounds 5 , 6 , 12 as well as 2,3,5,6-tetraphenylpyrazine ( 14 ) and in methylene chloride it gave 11 (16%) and small amounts of 4 , 5 , 14 , and acetophenone ( 15 ). On heating 4-phenyl-1,2,3-triazole ( 1 ) in n-hexadecane, elimination of nitrogen at 290° left phenylacetonitrile ( 2 ) as the only identified product. Similar pyrolysis of 4,5-diphenyl-1,2,3-triazole ( 9 ) produced 2,3,5,6-tetraphenylpyrazine ( 14 ) along with an intractable material. An efficient thermal isomerization of 2,3-diphenyl-2H-azirine ( 13 ) gave 2-phenylindole ( 17 ).     

Fabrication of superhydrophobic surfaces with hierarchical structure through a solution-immersion process on copper and galvanized iron substrates

Superhydrophobic surfaces were obtained on copper and galvanized iron substrates by means of a simple solution-immersion process: immersing the clean metal substrates into a methanol solution of hydrolyzed 1H,1H,2H,2H-perfluorooctyltrichlorosilane (CF3(CF2)5(CH2) 2SiCl3, FOTMS) for 3-4 days at room temperature and then heated at 130 degrees C in air for 1 h. Both of the resulting surfaces have a high water contact angle (CA) of larger than 150.0 degrees as well as a small sliding angle (SA) of less than 5 degrees . The formation and structure of the superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectrometry (EDX). SEM images showed that both of the resulting surfaces exhibited special hierarchical structure. The special hierarchical structure along with the low surface energy leads to the high surface superhydrophobicity.     

In situ hydrolysis of imine derivatives on Au(111) for the formation of aromatic mixed self-assembled monolayers: multitechnique analysis of this tunable surface modification

This paper presents a novel method for preparing aromatic, mixed self-assembled monolayers (SAMs) with a dilute surface fraction coverage of protonated amine via in situ hydrolysis of C═N double bond on gold surface. Two imine compounds, (4'-(4-(trifluoromethyl)benzylideneamino)biphenyl-4-yl)methanethiol (CF(3)-C(6)H(4)-CH═N-C(6)H(4)-C(6)H(4)-CH(2)-SH, TFBABPMT) and (4'-(4-cyanobenzylideneamino)biphenyl-4-yl)methanethiol (CN-C(6)H(4)-CH═N-C(6)H(4)-C(6)H(4)-CH(2)-SH, CBABPMT), self-assembled on Au(111) to form highly ordered monolayers, which was demonstrated by infrared reflection absorption spectroscopy (IRRAS) and X-ray photoelectron spectroscopy (XPS). A nearly upright molecular orientation for CF(3)- and CN-terminated SAM was detected by near edge X-ray absorption fine structure (NEXAFS) measurements. Afterward, the acidic catalyzed hydrolysis was carried out in chloroform or an aqueous solution of acetic acid (pH = 3). Systematic studies of this hydrolysis process for CN-terminated SAM in acetic acid at 25 °C were performed by NEXAFS measurements. It was found that about 30% of the imine double bonds gradually cleaved in the first 40 min. Subsequently, a larger hydrolysis rate was observed due to the freer penetration of acetic acid in the SAM and resultant more open molecular packing. Furthermore, the molecular orientation in mixed SAMs did not change during the whole hydrolysis process. This partially hydrolyzed surface contains a controlled amount of free amines/ammonium ions which can be used for further chemical modifications.     

Formation of 1,1,4,4-tetramethoxy-2,3,5,6-tetrahydroximinocyclohexane by the interaction of trinitrosophloroglucinol with hydroxylamine hydrochloride in methanol

1,1,4,4-Tetramethoxy-2,3,5,6-tetrahydroximinocyclohexane was obtained by the treatment of trinitrosoploroglucinol with hydroxylamine hydrochloride in methanol. Oxidation of the product with an alkaline solution of potassium hexacyanoferrrate(III) gave a mixture of the isomers 4,4,8,8-tetramethoxy-4H, 8H-benzo[1,2-c:4,5-c']bis[1.2.5]oxadiazole-1,7-dioxide.and 4,4,8,8-tetramethoxy-4H, 8H-benzo[1,2-c:4,5-c']bis-[1.2.5]oxadiazole-1,7-dioxide. Removal of the N-oxide groups from these compounds with triethyl phosphite followed by hydrolysis of the diketal groups gave 4,8-dioxo-4H, 8H-benzo[1,2-c:4,5-c']bis[1.2.5]-dioxazole. Reaction with malonodinitrile gave 4,8-di(dicyanomethylene)-4H, 8H-benzo[1,2-c:4,5-c']bis[1.2.5]-oxadiazole which is an analog of known electron acceptors. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Acaemy of Sciences, Novosibirsk 630090. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 549–553, April, 1997.     

The reaction of 2-acetoacetamidopyridines with phosgene. A route to novel 3-Acetyl-2-chloro-4H-pyrido[ 1,2-a] pyrimidin-4-ones

2-(Acetoacetamido)pyridine, 1 , and its 5-methyl derivative, 2 , with phosgene, gave 3-acetyl-2-chloro-4H-pyrido[1,2-a]pyrimidin- 4 -one, 5 , and 3-acetyl-2-chloro-7-methyl-4H-pyrido[1,2-a]-pyrimidin-4-one, 6 , respectively. The structures of these compounds followed from their elemental analyses, and interpretations of their uv, ir, pmr, and X-ray spectra. An alternative route to 5 and 6 , which sought first to react 1 and 2 with methyl - and benzyl chloroformates, was unsuccessful, and led, instead, to elimination of the acetoacetyl group with concomitant formation of the carbamate derivatives, 10 and 11 .