Symmetrical and Asymmetrical Bisphosphonate Esters. Synthesis, Selective Hydrolysis, and Isomerization

Summary. Two simple and efficient one-pot procedures for the synthesis of a series of α-branched N-heterocycle-substituted methane-1,1-bisphosphonates are outlined. In the first method, the parent halosubstrates were reacted with cyanomethylphosphonate followed by reaction with dialkyl phosphonates to give asymmetrical or symmetrical bisphosphonates (BPs). In the second approach, the same halocompounds were reacted with tetraethyl methyl-1,1-bisphosphonate to give the requisite BPs. Partial and complete hydrolysis of the prepared BPs were also investigated. The products contain functional groups advantageous for further synthetic modification as structural units for coupling with the drug.     

Reaction of 2,2-dinitromalononitrile with arylalkenes

2,2-Dinitromalononitrile reacted with phenylethene and 1-phenylpropene through intermediate aci-nitromalononitrile ester and subsequent 1,3-dipolar cycloaddition of the second alkene molecule with formation of substituted 5-phenyltetrahydroisoxazole-3,3-dicarbonitriles. Reactions of 2,2-dinitromalononitrile with 2-phenylpropene or p-methoxyphenylethene resulted in the formation of 2-(1-aryl-2-nitroethyl)-2-nitromalononitriles. 1,1-Diarylethenes reacted with 2,2-dinitromalononitrile to give conjugated 1,1-diaryl-2-nitroethenes due to steric hindrances.     

Polyaddition reactions of bisethyleneureas and 1,1,3,3-diethyleneurea with polymethylene dimercaptans in LiCl-dimethylformamide

Polyaddition reactions of 1,1′-tetramethylenebis(3,3-ethyleneurea) (IIa), 1,1′-octamethylenebis(3,3-ethyleneurea) (IIb), 1,1′-p-phenylenebis(3,3-ethyleneurea) (IIc), 1,1′-(4,4′-diphenylmethane)bis(3,3-ethyleneurea) (IId) and 1,1,3,3-diethyleneurea (III) with polymethylene dimercaptans were investigated. 1,1′-Polymethylenebis(3,3-ethyleneureas) and polymethylene dimercaptans successfully reacted at 80–95°C. in the presence of triethylamine to give poly(urea sulfides) with intrinsic viscosities up to 1.1 in about 90% yield when dimethylformamide, dimethylacetamide, or N-methyl-2-pyrrolidone containing lithium chloride as a solvent were used. The other ethyleneureas, however, failed to give high molecular weight polymers.     

Sulphur heterocycles from thiodiacetonitrile and sulphonyldiacetonitrilc

Thiodiacetonitrile reacted with α-diketones to form 5-cyano-2-thiophenecarboxamides and with α-keto esters to give 3-hydroxy-2,5-thiophenedicarbonitriles. Sulphonyldiacclonitrile condensed with α,β-unsaturated ketones to give 6-cyano-3,4-dihydro-1,1-dioxo-2H-thiopyran-2-carboxamides.     

1-(Aziridine) carbonyl chlorides and 1-(aziridine) carbonyl quaternary ammonium chlorides. Rearrangement to 2-(chloroalkyl) isocyanates

Aziridine reacted with phosgene in the presence of an acid acceptor or with 1,1′-carbonylbis(pyridinium) chloride to produce 1-(aziridine)carbonyl chloride (XII) or 1-(aziridine)carbonyl pyridinium chloride (XIII), respectively, as transient intermediates. Attempts to trap and observe (XII) and (XIII) at -10° were unsuccessful. These elusive materials underwent facile rearrangements to 2 - chloroethyl isocyanate under these conditions. Aziridine reacted with 1,1′-carbonylbis(triethylammonium)chloride (VII) at -20° to give 1-(aziridine) carbonyl triethylammonium chloride (X) as a transient intermediate which proceeded to 2-chloroethyl isocyanate. At -10° this reaction produced N,N-diethyl-1-aziridinecarboxamide. Aziridine reacted with a large excess of phosgene in the absence of an acid acceptor to give N-2-(chloroethyl) carbamoyl chloride (III), 1,1′-bis(2-chloroethyl) urea (IV) and 2-(β-chloroethylamino)-2-oxazoline hydrochloride (V). Possible mechanisms for these reactions are discussed.     

Directed metalation of pyridinesulphonamides. Synthesis of pyridine-fused isothiazoles and 1,2-oxathioles

4-Lithio-N-t-butylpyridine-3-sulphonamide reacted with benzophenone and carbon dioxide respectively to give the corresponding intermediates which on appropriate treatment gave isothiazolo[5,4-c]pyridin-3-one 1,1-dioxides. Metalation of 2- and 4-(N,N-dialkylaminosulphonyl)pyridines with lithium diisopropylamide (LDA) gave anions which reacted with benzophenone to give carbinols which thermally cyclised to 1,2-oxathiolo[3,4-b]pyridine and 1,2-oxathiolo[4,3-c]pyridine respectively.     

Synthesis of α,ω-bis(pyrazol-3-yl)alkanes: I. 1,4-bis(1-methyl- and 1-benzyl-5-chloro-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-3-yl)-butanes from 1,1,10,10-Tetrachlorodeca-1,9-diene-3,8-dione and 1,1-dimethyl- or benzylhydrazine

First representatives of bis-2-chloro- and 2,2-dichlorovinyl ketones, 1,10-dichlorodeca-1,9-diene-3,8-dione and 1,1,10,10-tetrachlorodeca-1,9-diene-3,8-dione, were synthesized by reaction of hexanedioyl dichloride with acetylene and 1,1-dichloroethene, respectively, in the presence of AlCl₃. 1,1,10,10-Tetrachlorodeca-1,9-diene-3,8-dione reacted with benzylhydrazine and 1,1-dimethylhydrazine to give 1,4-bis(1-benzyl-5-chloro-1H-pyrazol-3-yl)butane and 1,4-bis(5-chloro-1-methyl-1H-pyrazol-3-yl)butane, respectively.     

Three-Component Spiro Heterocyclization of Pyrrolediones with Indan-1,3-dione and Acyclic Enamines

Ethyl 4,5-dioxo-2-phenyl-4,5-dihydro-1H-pynole-3-carboxylates reacted with indan-1,3-dione and 3-amino-1-phenylbut-2-en-1-one or 3-aminobut-2-enenitrile to give 3-benzoyl-2-methyl-2′,5-dioxo-5′-prienyl-1,1′,2′,5-tetrahydrospiro[indeno[1,2-b]pyridine-4,3′-pyrroles] and 2-methyl-2′,5-dioxo-5′-phenyl-1,1′,2′,5-tetrahydrospiro[indeno[1,2-b]pyridine-4,3′-pyrrole]-3-carbonitriles, respectively.

     

Application of selective 1 : 2 addition of ketene N,N-acetal and isocyanates to novel polyamide syntheses

1,1-Bis(dimethylamino)ethylene (ketene N,N-acetal) (1) reacted with isocyanates to give either 1 : 1 adduct 3,3-bis(dimethylamino)acrylamides (3) or 1 : 2 adduct bis(dimethylamino)methylenemalonamides (4), depending on the amount of the charged isocyanate. 3 was obtained selectively in the case of isocyanate/1 = 1, while 4 was exclusively yielded in the case of isocyanate/1 = 2. Isothiocyanate showed similar reaction behavior as isocyanate. Polyaddition of 1 with diisocyanates afforded polyamides bearing a bis(dimethylamino)methylenemalonamide group with higher molecular weight. The obtained novel polyamides are soluble in various organic solvents, and reacted with diacid chloride to give crosslinked polymer quantitatively. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3079–3086, 1999     

Synthesis, Reactions, and Anti-inflammatory Activity of Heterocyclic Systems Fused to a Thiophene Moiety Using Citrazinic Acid As Synthon

Summary. A series of pyridines, pyrimidinones, and oxazinones were synthesized as anti-inflammatory agents using citrazinic acid (2,6-dihydroxyisonicotinic acid) as a starting material. Acryloyl pyridine was treated with cyanothioacetamide to give cyano pyridine-thione, which was reacted with ethyl chloroacetate to yield the corresponding amino ester. The ester was hydrolysed to the sodium salt, which was treated with acetic anhydride to afford 2-methyloxazinone, which was treated with ammonium acetate to afford 2-methylpyrimidinone followed by methylation with methyl iodide to yield 2,3-dimethylpyrimidinone. In addition, the oxazinone derivative was reacted with aniline or hydrazine hydrate to give 3-phenyl- or 3-aminopyrimidinones. The latter reacted with thiophene-2-carboxaldehyde or phenylisothiocyanate to afford Schiff’s bases or thiosemicarbazides. 3-Aminopyrimidinone was treated with phthalic anhydride or 1,2,4,5-benzenetetracarboxylic acid dianhydride or toluene-3,5-diisocyanate to afford the corresponding imide, bis-imide, and bis-semicarbazide derivatives. The pharmacological screening showed that many of these compounds have good anti-inflammatory activity comparable to Prednisolone^? as reference drug.     

Acetylenic ketones. Part VI. Reaction of aroylphenylacetylenes with hydrazine derivatives

The reaction of aroylphenylacetylenes (I) with acyl- or aroylhydrazines (II) gave ω-aroyl-acetophenone-N-acyl or N-aroylhydrazones (IV). The latter gave upon treatment with methanolic potassium hydroxide and with acetic anhydride in the presence of sodium acetate, the corresponding pyrazoles (V) and the N-acetylpyrazoles (VII and VIII), respectively. The acetylenic ketones ( 1 ) also reacted with methylhydrazine and 1,1-dimethylhydrazine to give 5-aryl-1-methyl-3-phenylpyrazoles (XII), and 1,1-dimethylhydrazine derivatives (XIII), respectively. When the latter compounds were heated with acetic anhydride, they gave the N-methylpyrazoles (XII).     

Diels–Alder Reactions with Cyclic Sulfones: VII. Synthesis of 1-Benzothiophene 1,1-Dioxide Derivatives

5-Arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-diones reacted with 5-isopropenyl-2,3-dihydrothio-phene 1,1-dioxide to give the corresponding ortho-addition products, 5-aryl-2',2',7-trimethyl-3,3a,5,6-tetra-hydro-2H-spiro[1-benzothiophene-4,5'-[1,3]dioxane]-4',6'-dione 1,1-dioxides. Their aminolysis resulted in opening of the 1,3-dioxane ring and formation of 4-carbamoyl-7-methyl-2,3,3a,4,5,6-hexahydro-1-benzo-thiophene-4-carboxylic acid 1,1-dioxide whose structure was determined by X-ray analysis. Reactions of the spiro adducts with amines and hydrazine hydrate afforded the corresponding mono- or dicarboxylic acid monoamides (hydrazide).     

Fluorinated 1,3-diketones, 2-trifluoroacetyl phenols and their derivatives: versatile reactants in phosphorus chemistry

The role of fluorinated β-diketones, their tautomers (keto–enols) and their derivatives as reagents towards λ³P compounds is reviewed, including 2-trifluoroacetyl phenols, possessing formally a keto–enol system, and their derivatives. In an ‘insertion’ reaction phosphine and the keto–enol tautomers of 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoropentan-2,4-dione furnished primary (S) or (R) α-hydroxy phosphines, whose enol functions probably isomerized the corresponding keto compounds. Further addition and isomerisation furnished 1,3α,5,7β-tetrakis(trifluoromethyl)-2-phospha-6-oxa-9-oxabicyclo[3.3.1]-nonan-3β,7α-diol and 1,7-trifluoromethyl-3,5-methyl-2,4,8-trioxa-6-phophaadamantane, exclusively one diastereomer in each case. The main mechanistic feature of these reactions is a consecutive diastereoselective hemiketal cyclization. 1,1,1,5,5,5-Hexafluoro- and 1,1,1-trifluoropentan-2,4-dione, as well as 2-trifluoroacetyl phenol and its imino derivatives reacted diastereospecifically with phosphonous acid dichlorides, RPCl₂ to give in a concerted mechanism thermally stable tricyclic λ⁵σ⁵P phosphoranes containing two five-membered rings and one six-membered ring. Surprisingly, the two CF₃ groups bonded to an sp³-hybridized carbon were in a cisoid arrangement having closest non-bonding FF distances of 301.4 or 273.5 pm. These findings reflect the ‘through space’ F---F coupling constants of the tricyclic phosphoranes (J_FF=4.0–7.0 Hz), in solution. 4,4,4-Trifluoro-3-hydroxy-1-phenyl-butan-1-one and methyl or phenyl phosphonous acid dichlorides gave similar tricyclic phosphoranes decomposing at ambient temperature to furnish 1,2λ⁵σ⁴-oxaphospholanes and (E)-1,1,1-trifluoro-4-phenyl-but-2-en-4-one. Dialkylphosphites and 1,1,1,5,5,5-hexafluoropentan-2,4-dione reacted to give either the (Z)-enol phosphonates or the respective γ-ketophosphonates from which in two cases four diastereomeric 2-oxo-2,5-dialkoxy-3,5-bis(trifluoromethyl)-3-hydroxy-1,2λ⁵σ⁴-oxa-phospholanes were obtained. 2-Trifluoroacetyl cyclohexanone, 4,4,4-trifluoro-3-trimethylsiloxy-1-phenylbutan-1-one, 1-benzoyl-2-trifluormethyloxirane, 1-benzoyl-2-trifluoro-methylaziridine, 2-trifluoroacetyl-1-trimethylsiloxybenzene and (trifluoroacetyl-1-phenyl) diethyl phosphate reacted with tris(trimethylsilyl) phosphite to give functionalized α-trimethylsiloxy phosphonates, which could easily be transferred into the respective phosphonic acids. In the case of an oxirane and an aziridine ketone no ring cleavage was observed. For 1,1′-(2-hydroxy-5-methyl-m-phenylene)-bis-ethanone and 1,1′-(2-trimethylsiloxy-5-methyl-m-phenylene)-bis-ethanone benzoxaphospholanes were obtained. Trialkyl phosphites and 1,1,1,5,5,5-hexafluoropentan-2,4-dione furnished cyclic phosphoranes containing the 3-hydroxy-3,5-bis(trifluoromethyl)-1,2λ⁵σ⁵-oxaphospholene structural element, stable at ambient temperature only in the case of one cyclic phosphite precursor. (E)-1,1,1-Trifluoro-4-phenyl-but-2-en-4-one and trimethylphosphite reacted to form 1,2λ⁵σ⁵-oxaphosphol-4-ene as the sole product. Results similar to the reaction of 1,1′-(2-hydroxy-5-methyl-m-phenylene)-bis-ethanone with diethyltrimethylsilylphosphite were obtained for trimethylphosphite and 2-trifluoroacetyl phenol where a deoxygenated phosphorane was found, easily hydrolyzed to give the respective phosphonic acid. With dialkylisocyanato phosphites and the keto components, 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoropentan-2,4-dione, 4,4,4-trifluoro-1-phenyl-1,3-butandione, 2-trifluoroacetyl cyclohexanone, 2-trifluoroacetyl phenol and 1,1′-(2-hydroxy-5-methyl-m-phenylene)-bis-ethanone reacted in a ‘double’ cycloaddition to form bicyclic phosphoranes containing the 4,8-dioxa-2-aza-1λ⁵σ⁵-phosphabicyclo[3.3.0]-oct-6-en-3-one ring system; for the imino derivatives of 2-trifluoroacetyl phenol a corresponding 8-oxa-2,4-diaza- system was generated. For (E)-1,1,1,5,5,5-hexafluoro-4-trimethylsiloxy-3-penten-2-one however, a cyclic spiroimino phosphorane was obtained which underwent a [2+2] cyclodimerization to form a diazadiphosphetidine. Dimethylpropynyl phosphonite and 1,1,1,5,5,5-hexafluoropentan-2,4-dione yielded diastereoselectively a bisphosphorane, namely 1,4-bis(trifluoromethyl)-3,6-dioxa-2,2,7,7-tetramethoxy-2,7-di(1-propynyl)-2,7-diphosphabicyclo[2.2.1] heptane. When trimethylsilanyl–phosphenimidous acid bis-trimethylsilanyl–amide, Me₃SiN=PN(SiMe₃)₂, was allowed to react with 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoropentan-2,4-dione, (E)-1,1,1,5,5,5-hexafluoro-4-trimethylsiloxy-3-penten-2-one, 2-trifluoroacetyl cyclopentanone, 2-trifluoroacetyl phenol and its imino derivatives, 2-imino-1,2λ⁵σ⁴-oxaphospholenes were found containing two diastereomers in each case, which added hexafluoroacetone across the P=N bond to give 1,3,2λ⁵σ⁵-oxazaphosphetanes.     

Synthesis,structures, and selected chemical properties of 2-chloro- and 2-bromo-1,1-diferrocenylcyclopropanes

2-Chloro- and 2-bromo-1,1-diferrocenylcyclopropanes were synthesized as Z- and E-isomers with respect to the ferrocenyl substituent having a bisector orientation. The structure of Z-2-chloro-1,1-diferrocenylcyclopropane was confirmed by X-ray diffraction analysis. Treatment of the resulting monohalides with potassium tert-butoxide in dimethyl sulfoxide afforded 3,3-diferrocenylcyclopropene in 20% yield. The small ring in halogen-substituted diferrocenylcyclopropanes and diferrocenylcyclopropene is readily cleaved to give predominantly 3-ferrocenyl-1H-cyclopentaferrocene.     

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     

Reactions of indoles with ortho esters,N,N-dimethylformamide and N,N-dimethylacetamide dialkyl acetals

Indole and N-methylindole react with oxa stabilized carbocations generated in situ from orthoformates to yield tris(3-indolyl)methane. The unsymmetrical isomers, e.g. 2-(N-methyl-3-indolyl)di(N-methyl-3-indolyl)-methane ( 4 ), were not formed as established by an independent synthesis. N,N-Dimethylacetamide dimethyl-acetal reacted with 2-alkyl substituted indoles to produce 1,1-bis(3-indolyl)ethanes ( 3 ).     

Alkylsulfamoyl Chlorides as Key Units in the Synthesis of Novel Biologically Active Compounds for Crop Protection

Due to their bifunctional character, alkylsulfamoyl chlorides are versatile units for the synthesis of heterocycles, polar sulfamates, and sulfonamides. In the last decade, synthetic methods of general preparative use have been developed, by means of which amine hydrochlorides, isocyanates, aziridines or tertiary alcohols can be reacted with suitable sulfuric acid derivatives to give novel, variously substituted alkylsulfamoyl chlorides. These compounds can subsequently be converted either to previously unobtainable N-alkoxyalkyl-N-alkylsulfamoyl chlorides or to novel heterocycles of the type 1H-2,1,3-benzothiadiazin-4-one-2,2-dioxide, 2H-1,2,6-thiadia-zin-3-one-1,1-dioxide and 2H-1,2,4,6-thiatriazin-5-one-1,1-dioxide; these compounds are examples of interesting models which illustrate the relation between the structure and the action of the compound, and in some cases lead to highly selective, ecologically unobjectionable herbicides. On the other hand, the alkylsulfamoyl chlorides themselves can be N-acylated to give further 3- to 5-atom bifunctional synthesis units, with which novel heterocyclic syntheses can be carried out. Further uses of the alkylsulfamoyl chlorides include the preparation of biologically active sulfamates, and cycloaddition reactions of N-sulfonylamines prepared in situ.     

Preparation of silyl-protected γ-hydroxylated α,β-unsaturated acetylenic ketones and their reactions with some nucleophiles

A number of 5-siloxylated 1,1-diethoxy-3-alkyn-2-ones were prepared from the corresponding ketals. The t-butyldiphenylsiloxy derivatives were stable, whereas the trimethylsilyl analogs were unstable. The former compounds were reacted with diethylamine, lithium dimethylcuprate, and 1,3-propanedithiol and gave Michael adducts in good to very good yields. The amine and cuprate gave the conjugated alkenones, the former in a stereospecific manner (Z), the latter stereospecifically (E) in one case but otherwise stereoselectively with an E preponderance. With the dithiol bisaddition occurred, and the corresponding 1,3-dithiane was obtained in excellent yield. Attempts to make 1,3-dithianes from 1,3-propanedithiol and 1,1-diethoxy-4-diethylaminoalk-3-en-2-ones failed.     

Asymmetric Synthesis of α‐Substituted N‐Methylsulfonamides

A novel amine auxiliary for the asymmetric synthesis of α‐substituted N‐methylsulfonamides is described. The reaction of 4‐([1,1′‐biphenyl]‐4‐yl)‐2,2‐dimethyl‐1,3‐dioxan‐5‐amine ( 16 ) with various aliphatic sulfonyl chlorides afforded the corresponding sulfonamides, which were lithiated and subsequently reacted with electrophiles to give the corresponding products in high yields and good‐to‐excellent asymmetric inductions (de 83–95%). Racemization‐free cleavage of the auxiliary led to the α‐alkylated N‐methylsulfonamides in acceptable yields and high enantiomer purities (ee 91 to ≥98).     

Synthesis, Reactions, and Anti-arrhythmic activity of Substituted Heterocyclic Systems Using 5-Chloroanisic Acid as Starting Material

Summary. A series of substituted heterocyclic systems were prepared from N1-[4-(4-fluorocinnamoyl)phenyl]-5-chloro-2-methoxybenzamide, which was prepared from the corresponding 5-chloroanisic acid (2-methoxy-4-chlorobenzoic acid) as starting material. Treating of the cinnamoyl derivative with hydrazine hydrate in dioxane afforded a pyrazoline, which was reacted with morpholine and paraformaldehyde to give the N-substituted pyrazoline. Acylation of pyrazoline with acetyl chloride in dioxane afforded the N-acetyl analogue. Also, the cinamoyl derivative was reacted with methylhydrazine, phenylhydrazine, or ethyl cyanoacetate to yield the corresponding N-methyl-, N-phenylpyrazoline, pyrane, and pyridone derivatives. Condensation of the cinnamoyl derivative with cyanothioacetamide gave the pyridinethione derivative, which was treated with ethyl chloroacetate affording the ethyl carboxylate derivative. Also, it was reacted with malononitrile or ethyl acetoacetae to give the cyano amino analougues and ethyl carboxylate, which was reacted with methylhydrazine to give the (indazolyl)phenyl derivative. On the other hand, reaction of cinnamoyl derivative with acetyl acetone afforded the cyclohexenyl derivative, which was reacted with hydrazine hydrate to give the [methylindazolyl]phenyl derivative. Condensation of the cinnamoyl derivative with guanidine hydrochloride or thiourea afforded the aminopyrimidine derivative and thioxopyrimidine. The latter was condensed with chloroacetic acid to yield a thiazolopyrimidine, which was condensed with 2-thiophenealdehyde to yield the arylmethylene derivative, however, it was also prepared directly from thiopyrimidine by the action of chloroacetic acid, 2-thiophenealdehyde, and anhydrous sodium acetate. The pharmacological screening showed that many of these compounds have good anti-arrhythmic activity and low toxicity.