The acid-mediated ring opening reactions of α-aryl-lactams

4-Aryl-azetidin-2-ones (β-lactams) undergo ring opening with triflic acid to give cinnamamides which, in benzene, react further to give 3-aryl-3-phenyl-propionamides. Prolonged reaction times in benzene give 3,3-diphenyl-propionamide via an aryl/phenyl exchange. Lactams of ring size 7 and higher also ring open, but only 7- and 8-membered rings give pure diphenylalkylamides. AlCl(3) only ring opens the 4-aryl-azetidinones.     

Novel Synthesis of Dihydroquinoxalinylpyridazine Derivatives

Methylquinoxaline derivative 1 undergoes bromination to give bromomethyl quinoxaline 2 , which could be transferred to cyanomethyl quinoxaline 3 . The latter compound 3 readily coupled with arene diazonium salts to give hydrazone derivatives 5a‐c . Compounds 5a,b reacted with active methylene reagents to give the target ring system, quinoxalinylpyridazine derivatives 8a‐c . Compound 1 reacted with DMFDMA to give the enamine derivative 9 , which coupled with arene diazonium salts to give the aldehydic hydrazone derivatives 10a‐c . Compound 10 reacted with active methylene compounds to give quinoxalinylpyridazine derivatives. UV characterization of some of the prepared compounds was reported.     

亚磺化脱卤研究 X: 全氟及多氟溴代烷的反应研究

本文报道溴代全氟烷和α,ω-二溴代全氟烷在亚磺化脱卤反应体系中与烯烃的反应及其与相应的碘代全氟烷的区别. 合成了全氟仲溴代烷CF3CFBrOCF2CF(CF3)O(CF2)2SO2F(7), 它与烯烃反应可得到1:1的加成物. 7的水解产物CF3CFBrOCF2CF(CF3)O(CF2)2SO3Na(11)与连二亚硫酸钠反应只得到氢化脱溴产物. 多氟溴化物CF3CBr2X(13X=F; 14X=Cl; 15X=Br)经亚磺化脱溴可得到相应的亚磺酸钠盐CF3CBrXSO2Na(16X=F; 17X=Cl; 18X=Br), 其中间体多氟烷自由基可用烯烃捕集, 得到高产率的1:1加成产物.     

Synthesis and reactivity of 3-(trichlorogermyl)propanoic acid and 3-(triphenylgermyl) propanoic acid

3-(Trichlorogermyl)propanoic acid (la) reacts with phenylmagnesium bromide in malar ratio 1:4 to give 3-(triphenylgermyl)propanoic acid (2a).In the compounds la and 2a theβ-carboxylic functional group shows some unusual properties when they react with excess of phenylmagnesium bromide.The compound la reacts with phenylmagnesium bromide in molar ratio 1:5 to give phenyl 2-(triphenylgermyl)ethylketone (3a) and in molar ratio 1:6 to give l,l-diphenyl-3-(triphenylgermyl)propanol (4a).The compound 2a reacts with phenylmagnesium bromide in molar ratio 1:2 to give 3a and in molar ratio 1:3 to give 4a also.Dehydration of the compound 4a with dilute hydrochloric acid seems especially easy.Moreover,the compound la reacted with phenylmagnsium bromide in molar ratio 1:6,then the mixture was treated with dilute hydrochloric acid to give 1,1-diphenyl-3-(triphenylgermyl)-1-propene (5a) in one pot reaction.Alkyl Ge-C bond in the compound 5a can be cleaved selectively by lithium aluminium hydride ( LiAlH4) in good yiel     

四氟乙烯齐聚体的反应: II.四氟乙烯五聚体和烯丙醇的反应及反应产物的转化

The reaction of perfluoro- (3, 4-dimethyl-3-ethylhexene-(2)) (1) with allyl alcohol under different conditions gave different products. Compound 1 reacted with sodium allyl alcoholate yielding 2-(1'-allyloxy-tetrafluoroethyl)-perfluoro(3-methyl-3-ethylpentene- (1))(2). In the presence of triethylamine, 1 reacted with allyl alcohol to give 2-allyloxy-perfluoro (3, 4-dimethy1-4-ethylhexene- (2))(3), and in the presence of acetone and K2CO3 to give compound 4. These reactions all gave allyl-3-trifluoromethyl-3- pentafluoroethyl-2,2-dihydro-pentafluorovalerate (5a) as byproduct. Compound 1 reacted with allyl alcohol in the presence of triethylamine at 20-22`C to give 2, at 30-35`C to give a mixture of 2 and 3 and at 35-40`C to give a mixture of 3 and 5a respectively. Compound 2 was transformed to compound 4 in acetone and in the psesence of K2CO3, \o\ compound 5a or 5b in the corresponding alcohol and to compound 6 on reacting with dimethylamine. Compound 2 as well as 3 was converted to perfluoro-(3-ethyl-2,3,4,5- tetramethyl-2,3-dihydrofuran) (7) by KF in sulpholane.     

Oxiranylidene intermediate in the reaction of trans-2-chloro-3- tert-butyloxirane with sodium phenoxide.

The reaction of trans-2-chloro-3-(t-butyl)oxirane with sodium phenoxide in acetonitrile to give trans-2-phenoxy-3-(t-butyl)oxirane involves α-elimination to give an oxiranylidene which undergoes a stereoselective stepwise addition of phenol to give product.     

Direct chlorination of alcohols with chlorodimethylsilane catalyzed by a gallium trichloride/tartrate system under neutral conditions

The reaction of secondary alcohols 1 with chlorodimethylsilane (HSiMe(2)Cl) proceeded in the presence of a catalytic amount of GaCl(3)/diethyl tartrate to give the corresponding organic chlorides 3. In the catalytic cycle, the reaction of diethyl tartrate 4a with HSiMe(2)Cl 2 gives the chlorosilyl ether 5 with generation of H(2). Alcohol-exchange between the formed chlorosilyl ether 5 and the substrate alcohol 1 affords alkoxychlorosilane 6, which reacts with catalytic GaCl(3) to give the chlorinated product 3. The moderate Lewis acidity of GaCl(3) facilitates chlorination. Strong Lewis acids did not give product due to excessive affinity for the oxy-functionalities. Although tertiary alcohols were chlorinated by this system even in the absence of diethyl tartrate, certain alcohols that are less likely to give carbocationic species were effectively chlorinated using the GaCl(3)/diethyl tartrate system.     

6-Coordinate tungsten(VI) tris-n-isopropylanilide complexes: products of terminal oxo and nitrido transformations effected by main group electrophiles

The nitridotungsten(vi) complex NW(N[i-Pr]Ar)(3) (-N, Ar = 3,5-Me(2)C(6)H(3)) reacts with (CF(3)C(O))(2)O followed by ClSiMe(3) to give the isolable trifluoroacetylimido-chloride complex -(NC(O)CF(3))Cl, with oxalyl chloride to give cyanate-dichloride -(OCN)(Cl)(2), and with PCl(5) to give trichlorophosphinimide-dichloride -(NPCl(3))(Cl)(2). The oxo-chloride complex -(O)Cl, obtained from -N upon treatment with pivaloyl chloride, reacts with PCl(5) to give trichloride -(Cl)(3). Synthetic and structural details are reported for the new tungsten trisanilide derivatives.     

Reaction of cis-3-bromo-1,2-dibenzoylpropene with amines

The reaction of cis-3-bromo-1,2-dibenzoylpropene (1) with amines proceeds by means of a substitution-rearrangement attack to give the 2-(α-aminoacetophenonyl)acrylophenones ( 2 ). Like similar structures, 2 undergoes further substitution-rearrangement by amines to give 3-benzoyl-5-phenylpyrroles ( 5 ) and an enaminoketone, α-acetophenonyl-β-aminoacrylophenone ( 3 ). Competitive with substitution-rearrangement, amine addition to 2 followed by loss of hydrogen and then water leads to formation of the 3-benzoyl-4-amino-5-phenylpyrroles ( 4 ). The enaminoketones ( 3 ) by contrast with 2 are quite stable. Structure 2 when in polar solvents or in the presence of amines undergoes substitution-rearrangement to give 3 , which can be induced to give the pyrroles ( 5 ) when exposed to acid conditions. When neat or in solvents of low polarity, 2 undergoes intermolecular substitution-rearrangement-dehydration to give 5 almost exclusively. A novel addition reaction of 3-benzoyl-5-phenylfuran involving attack by isopropyl- or cyclohexylamine provides a quantitative method of synthesizing the appropriate N-substituted examples of 3 and an efficient method of deriving the corresponding pyrroles ( 5 ).     

Reactions of the sterically hindered organosilicon diol (Me3Si)2C(SiMe2OH)2 and some of its derivatives

The diol R₂C(SiMe₂OH)₂ (R = Me₃Si) has been shown to react with: SO₂Cl₂ to give R₂ Me₂; SOCl₂ to give R₂C(SiMe₂Cl)₂; Me₃SiI or Me₃SiCl to give R₂C(SiMe₂OSiMe₃)₂; R′COCl; (R′ = Me or CF₃) to give R₂C(SiMe₂O₂CR′)-(SiMe₂Cl); (R′CO)₂O (R′ = Me or CF₃ to give R₂C(SiMe₂O₂CR′)₂; with MeOH containing acid to give R₂C(SiMe₂OMe)₂; with neutral MeOH to give R₂C-(SiMe₂OMe)₂ and probably R₂ Me₂; MeLi to give R₂C(SiMe₂OLi)₂ (and the latter to react with PhMeSiF₂ to give R₂ Me₂). The diacetate R₂C(SiMe₂O₂CMe)₂ reacts with CsF in MeCN to give R₂C(SiMe₂F)₂; it does not react with NaN₃ or KSCN in MeCN, but the bis(trifluoroacetate) reacts with these salts with KOCN to give R₂C(SiMe₂X)₂ (X = N₃, NCS, NCO).     

Some reactions of 3-hydroxythietane

3-Hydroxythietane is readily oxidized by hydrogen peroxide in acetone or acetic acid solution at 0°C to give 3-hydroxythietane-1-oxide. 3-Thietyl acetate is oxidized similarly. 3-Hydroxythietane-1-oxide reacts vigorously with SOCl₂ in benzene, with the formation of bis-2, 3-dichloropropyl disulfide. 3-Hydroxythietane-1,1-dioxide reacts with phosgene to give 3-thietyl-1, 1-dioxide chloroformate, which gives with diethylamine 3-thietyl-1, 1-dioxide N, N-dimethylcarbamate. Sodium peroxide and barium perbenzoate with the chloroformate give the corresponding di-(3-thietyl-1, 1-dioxide) peroxydicarbonate and 3-thietyl-1, 1-dioxide perbenzoate.     

2-(3-ethyl-2,2-dimethylcyclobutyl-methyl)-4(3H)-quinazolinones

Anthranilic acid and its 5-bromo and 4-chloro derivatives react with pinanoic and pinonoic acid chlorides to give the corresponding N-acyl derivatives. The pinanoyl derivatives give the corresponding 2-(3-ethyl-2,2-dimethyl-cyclobutylmethyl)-4-(3H)-quinazolinones when refluxed in formamide. Pinanoylanthranilic acid reacts with dicyclohexylcarbodiimide to give 2-(3-ethyl-2,2-dimethylcyclobutylmethyl)benz-3,1-oxazin-4(H)-one and subsequently with hydrazine hydrate to give 3-amino-2-(3-ethyl-2,2-dimethylcyclobutylmethyl)-4(3H)-quinazolinone. Refluxing of the pinanoyl- and pinonoylanthranilic acids with acetic anhydride gives acetylanthranilic acid, and pinonoylanthranilic acid gives 4(3H)-quinazolinone with formamide.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lanet.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 811–817, June, 1999.     

阳离子光固化活性单体氧杂环丁烷的合成及表征

以3-乙基-3-羟甲基氧杂环丁烷为原料，与甲基磺酰氯磺酰化，得到3-乙基-3-甲磺酰基甲基氧杂环丁烷；在碱性条件下，以PEG600作相转移催化剂，用3-乙基-3-甲磺酰基甲基氧杂环丁烷与乙二醇醚化得到2-[（3-乙基-3-氧杂环丁基）甲氧基]乙醇；然后与甲基丙烯酸甲酯进行酯交换得到目的产物2-[（3-乙基-3-氧杂环丁烷）甲氧基]甲基丙烯酸乙酯。3-乙基-3-羟甲基氧杂环丁烷与3-溴丙烯反应，生成3-乙基-3-[（2-丙烯-1-基氧基）甲基]氧杂环丁烷，然后在氯铂酸的催化下，与三乙氧基硅烷反应得到3-乙基-3-[[3-（三乙氧基硅）丙氧基]甲基]氧杂环丁烷。产物经红外光谱和核磁共振谱表征得到确证。     

Heterocycles of biological importance. Part 1. Novel synthesis and biological activity study of 5-Alkyl and 5-Aryl-7-aminopyrazolo[1,5-a]-pyrimidines from allenic or acetylenic nitriles and 3-aminopyrazole

Allenic nitriles react with 3-aminopyrazole in ethanol or dimethylformamide to give 5-alkyl-7-aminopyrazolo[1,5-a]pyrimidines 5 of pharmaceutical interest in good yields. 3-Phenylpropynenitrile reacts with 3-aminopyrazole in a similar manner to give the aryl compound 8 .     

褪黑激素的合成与表征

以吲哚为起始原料,经4步反应合成了褪黑激素(MLT) 吲哚(1)在甲醇中羟基化得到5-羟基吲哚(2),(2)同2-氯乙胺在乙酸乙酯中进行胺乙基化反应得到5-羟基色胺(3),(3)与硫酸二甲酯在甲苯中对羟基进行醚化,得到5-甲氧基色胺(4),(4)经乙酰化得到产物MLT,收率80%     

A divergent synthesis of functionalized unsaturated delta-lactones from alpha-alkenoyl-alpha-carboxyl ketene dithioacetals

A divergent synthesis of functionalized unsaturated delta-lactones 2, 3, 4, and 5 has been developed starting from the readily available alpha-alkenoyl-alpha-carboxyl ketene dithioacetals 1 in high to excellent yields under mild reaction conditions. Thus, 6-substituted 3-(1,3-dithiolan/dithian-2-ylidene)-3H-pyran-2(6H)-ones 2, obtained from a consecutive reduction with NaBH4 and acidic workup of 1 via a novel vinylogous Pummerer cyclization, can be further transformed into alpha-pyranones 3, 4, and 5 upon a sequential isomerization catalyzed by triethylamine (to give 3), followed by dethioacetalization (to give 4) or a formylation with Vilsmeier reagent (to give 5).     

Synthesis of new 1,2,4-triazolines and 1,3,4-thiadiazolines from bithioureas

2,4-Disubstituted thiosemicarbazides 1 react with acyl isothiocyanates to give bithioureas 2 , which by the action of sodium ethanolate cyclize to 1,2,4-triazoline-3-thiones 3 and 5 , respectively. Treatment of 2 with methyl iodide yields 1,3,4-thiadiazoline-2-imines 8 isomeric with 3 . Compound 8d undergoes a thermal induced DIMROTH rearrangement to give 3d in good yield.     

Lithiation of 3-(Acylamino)-2-unsubstituted-, 3-(Acylamino)-2-ethyl-, and 3-(Acylamino)-2-propyl-4(3H)-quinazolinones: Convenient Syntheses of More Complex Quinazolinones(1)

3-(Pivaloylamino)- and 3-(acetylamino)-4(3H)-quinazolinones react with alkyllithium reagents to give 1,2-addition products in very good yields. Lithiation takes place with LDA and is regioselective at position 2. The lithium reagents thus obtained react with a variety of electrophiles to give the corresponding substituted derivatives in very good yields. Reactions of the lithium reagents with iodine give oxidatively dimerized cyclic structures. 3-(Pivaloylamino)- and 3-(acetylamino)-2-ethyl-4(3H)-quinazolinones and 3-(pivaloylamino)- and 3-(acetylamino)-2-propyl-4(3H)-quinazolinones are lithiated at the benzylic position with LDA. The lithium reagents so produced also react with a variety of electrophiles to give the corresponding 2-substituted-4(3H)-quinazolinone derivatives in very good yields. However, lithiation of 3-(acylamino)-2-(1-methylethyl)-4(3H)-quinazolinones was unsuccessful, as were lithiations of compounds having a diacetylamino group at position 3. The amide groups have been cleaved in good yield under basic or acidic conditions from some of the products to provide access to the free amino compounds.     

The reactions of some ortho-substituted anilines with various α,β-acetylenic ketones. A route to substituted quinolines

The reactions of some ortho-substituted anilines with various α,β-acetylenic ketones were investigated as a route to 4-alkyl-, 4-aryl-, 4-hydroxy-, and 4-amino-3-quinolyl ketones. The anilines examined were 2-aminoacetophenone ( 1 ), 2-aminobenzophenone ( 2 ), anthranilonitrile ( 3 ), methyl anthranilate ( 4 ), and ethyl anthranilate ( 5 ). The acetylenic ketones used were 1,4-diphenyl-2-butyne-1,4-dione ( 6 ), 3-butyn-2-one (7), 1,3-diphenyl-2-propyn-1-one ( 8 ), and 4-phenyl-3-butyn-2-one ( 9 ). The acetylenic ketones typically reacted with the anilines to give enamines; however, exceptions were found. Acetylene 6 reacts with 3 to give the enamine ( 13 ) along with a small amount of 2,3-dibenzoyl-4-quinolamine ( 14 ). The reactions of 1 or 2 with 6 give the respective quinoline derivatives directly. Acetylene 8 reacts with 2 to give 3-benzoyl-2,4-diphenylquinoline ( 22 ) directly, whereas no reaction occurs between 8 and 1 or 3 . Acetylene 9 does not react with 1, 2 , or 3 . The enamines exist as the intramolecularly hydrogen bonded isomers and usually undergo cyclization with 5 molar equivalents of methanolic sodium methoxide to give quinoline derivatives. The 4-quinolinols exist predominantly as the 4-quinolinone tautomer.     

O—Maltosylation of Heterocyclic Ketene Aminals

The stereoselective synthesis of O-maltosides by reacting benzoyl-substituted heterocyclic ketene aminals 1 or 2 with acetylated maltosyl bromide 3 was investigated.Compounds 1 or 2 reacted with 3 in the presence of mercuric cyanide to give O-maltosides 4 or 5 with E-configuration.While 1 reacted with 3 in the presence of calcium hydride to give O-maltosides 6 with Zconfiguration.