The synthesis of 4-phenyl, 6-anisylsalicylic acid and 4-anisyl, 6-phenylsalicylic acid are described. The synthesis of 3-phenyl, 1-hydroxyfluorene and 3-anisyl, 1-hydroxyfluorene are reported.
A wide variety of 2-phosphono-1,1,4,4-tetrathio-1,3-butadienes (i.e. phosphonobisketene tetrathioacetals) was first synthesized from tetraethyl 2-phosphonosuccinate and thiols in the presence of organoaluminum reagent. The phosphonobisketene tetrathioacetals were readily deprotonated and the resulting anions were reacted with electrophiles such as Me3SiCl, Bu3SnCl, and Br-2 to afford hexa-substituted 1,3-dienes. Acylated phosphonobisketene tetrathioacetals were synthesized by the ,Friedel-Crafts reaction of the phosphonobisketene tetrathioacetals with acid chlorides. New synthesis of poly functionalized furans and thiophenes from the phosphonobisketene tetrathioacetals was also developed.
The reaction of 1-methyl-1-cyanohydrazones with methyl trifluoromethane sulfonate allows the direct preparation of 2-(methylamino)-1-methyl imidazoles as their triflic acid salts. The reaction pathway is believed to involve the formation of the 1-cyano-1,2-dimethyl ene-hydrazine derivative, which then undergoes a [3,3] rearrangement at room temperature, followed by an in situ cyclisation. None of the intermediates could be isolated or observed by H-1 NMR. Thus, the 2-(methylamino)-1-methyl imidazoles are obtained in good to average yields In two steps from the corresponding ketones and 1-methyl-1-cyanohydrazine.
Selectivity of ring opening reactions of the oxazolo[3,2-a]pyridinium cation in reactions with nucleophiles (cleavage of either C5-N bond or C 8a-0 bond) is reviewed, and the novel direction of ring opening (cleavage of C 2-O) bond is discovered. 2-Phenyloxazolo[3,2-a]pyridinium perchlorate in reaction with MeONa is transformed to l-[l,l-dimeth oxy-l-phenylethyl-2] -2-pyridone. Crystal structures of the final ketal and the starting material are reported, and the clear alternation of length of C-C bonds in both molecules is observed.
The ortho photocycloadducts, formed on irradiation of 3-tert-butyl-4-phenoxybut-1-ene (1a) and 3-acetoxy-4-(4-methoxyphenoxy)but-1-ene (1b) at 254 nm, underwent in situ rearrangement to tricyclic structures 4a, 5a, and 5b, 5b', respectively. Hydration of the vinyl ether function in 5a led to 6a, while a similar secondary reaction of 5b afforded 8b. A detailed NMR investigation of the rearranged ortho photocycloadducts of both 1a and 1b revealed not only the relevant structures, but also furnished configurational and conformational details.
Treatment of 5-O-benzoyl-1,3-dioxane (5) under bar with acetylchloride gave (3-acetoxy-2-O-benzoyl-1-propoxy)methylchloride (6) under bar in 95% yield. The heterocycles <(7a-c)under bar> were alkylated with (6) under bar. The N-1-alkylated products <(8a-c)under bar> (regioselectively obtained in 60-80%) were deprotected to give 4-alkylthio-1-[(2,3-dihydroxy-1-propoxy)methyl]-1H-pyrazolo[3,4-d]pyrimidines <(9a-c)under bar> in good yields. The 1-[(2,3-dihydroxy-1-propoxy) methyl]-4-methylthio-1H-pyrazolo[3,4-d]pyrimidine <(9a)under bar> was served as the precursor for the preparation of the 4-amino <(9d)under bar>, 4-methylamino <(9e)under bar>, 4-dimethylamino <(9f)under bar>, 4-benzylamino <(9g)under bar> and 4-methoxy <(9h)under bar> analogues.
Trichloroethylene, which is turned into dichloracetylene (DCA) under PTC conditions, reacts with a series of primary alcohols to form1,2-dichlorovinyl aliphatic ethers in a good yield (73-87%).
The potential energy surfaces corresponding to the Beckmann rearrangement (BR) of a series of aliphatic and cyclic alkanone oximes have been explored using density functional theory (DFT). In order to probe the reactivity of cyclohexanone oxime, the basic component in the industrial production of nylon-6, different model compounds were examined including formaldehyde oxime, acetone oxime, cyclopropanone oxime, cyclobutanone oxime, cyclopentanone oxime and cyclohexanone oxime itself. Geometries and energies were calculated using the B3LYP functionals in conjunction with the 6-31G(d,p) basis set. The influence of alkyl substitution in both aliphatic and cyclic forms on the simplest gas phase systems does not change the reaction pattern of the unsubstituted species and suggests that the most favored path remains as follows: protonation of oxime --> N-protonated species --> 1,2-H-shift --> O-protonated species --> migration-elimination --> fragmentation products, in which the 1,2-H-shift connecting both protonated isomers is rate-determining While methyl substituents on C of the oxime have only a small effect on the rate-controlling energy barrier, they significantly modify the fragmentation barrier. A similar trend occurs when ring structures are considered. Overall, it is confirmed that the difficulty, if any, in converting an alkanone oxime to BR product resides in the formation of its O-protonated form, indirectly from the more stable N-protonated form, rather than in the conversion of the O-protonated form into its products.
The reaction of 2-methylmercapto-4-phenyl-1,5-benzodiazepin with some aminoacids leads to new annulated 1,5- benzodiazepine derivatives. All the products have been characterized by H-1 NMR, MS and IR spectroscopies.
Metal(II) chelates of the Schiff base ligand derived from 2-formylcyclohexanone with o-phenylenediamine have been prepared and characterized. The isolated complexes are of the type ML.xH(2)O where M=Ni(II): Cu(II), Co(II), Zn(II), Pb(II), and UO2(VI) and where H(2)L stands for the bis (2-formylcyclohexylidene) o-phenylenediamine Schiff base ligand. A trinuclear Cu(II) complex of the formula Cu(2)L(2).CuCl2.3H(2)O was also prepared. The chelates were characterized by elemental analyses, IR, H-1 NMR and UV-Visible spectra as well as conductivity and magnetic measurements. It has been found that the ligand behaves as an ONNO quadridentate didasic chelator and that the complexes are non-electrolytes in DMF. The mode of bonding and geometrical structure are suggested.
Starting from meso-tetra(p-carboxyphenyl)porphyrin via the tetra-acid chloride, three meso-tetra substituted amides have been prepared and characterized by UV (Soret bands), H-1 and C-13 NMR.
New 3-vinylindolizines have been synthesized by two methods. The first strategy calls for the Wittig olefination of 3-acylindolizines with methylenetriphenylphosphorane or methoxymethylenetriphenylphosphorane. The best yields are obtained when the ylid is formed at room temperature and the condensation in refluxing THF. The required 3-acylindolizines were obtained by direct acylation of indolizines or by 1,3-dipolar cycle-additions to acylmethylpyridinium ylids. The following 3-isopropenylindolizines were made with good yields: unsubstituted (18,85%), 2-methyl (10,98%), 2-C6H5 (17,95%), 1-COOMe (20,98%), 1-COOMe-2-C6H5 (22,91%), 1,2-di-COOMe (24,58%). Also synthesized are the following 3-alpha-styrylindolizines: 2-C6H5 (19,99%), 1-COOMe (21,93%), 1-COOMe-2-C6H5 (23,87%), 1,2-diCOOMe (25,66%). 3-(alpha-Methyl-beta-methoxyvinyl)indolizines E (26,40%) and Z (27,40%) were also obtained. The second strategy involves the 1,3-dipolar cycle-addition of dipolarophiles to allylpyridinium ylids. The following new 3-vinylindolizines have been sythesized: 1-carbomethoxy-3-vinylindolizine (30,21%), 1,2-dicarbomethoxy-3-vinylindolizine (31,16%), 1-carbomethoxy-3-beta-styrylindolizine (33,43%), 3-beta-styrylindotizine (34,17%), 1-carbomethoxy-3-(beta-carbomethoxy)vinylindolizine 38 (31%).
We have shown that contrary to the literature indications, phenyl isocyanate can react in very mild conditions (20 degrees) with cytosine, thymine, uracil, and adenine if these reactions are carried out in homogeneous medium (DMSO). As for guanine, the chief reason of its non-reactivity in the same conditions is its insolubility in this solvent.
We report a synthesis of glutamic acid analogs, 1-aminocyclopropan-1,2-dicarboxylic acid derivatives, by reaction of ethyl diazoacetate with N-protected methylene glycinates in the presence of achiral and chiral copper complexes. The cyclopropanation is effective with these catalysts but the Pfaltz chiral complex did not induce any enantioselectivity.
Six new solid ternary complexes of lanthanide with D-Camphoric acid and I,10-phenanthroline being formulated here as Ln(2)(Phen)(4)L-3 [Ln=La(III), Pr(III), Sm(III), Eu(III), Tb(III) and Ho(III), Phen=1,10-phenanthroline and L=D-camphoric acid] have been synthesized and characterized on the basis of elemental analysis, molar conductance, UV, IR, XPS, Optical rotatory dispersion(ORD) and fluorescence spectrum. An eight coordinated binuclear bonding model is proposed for the complexes.
We report here a one-step synthesis of [1,2,4]triazolo[4,3-d][1,4]benzodiazepin 4, 5, and [1,2] oxazolo[5,4,b][1,4]benzodiazepine 6-8 by 1,3-dipolar cycloaddition of nitrilimines and nitrile oxides with the benzodiazepine 3.
The synthesis of 1-(N-benzimidazolyl)-3-(substituted dihydropyridino)-propan-2-ol were described and screened for its antibacterial and antifungal activity. The structures of the synthesised compounds were confirmed by LR, NMR and elemental analysis.
Norbornadiene was reacted with 2-methyl-3-butin-2-ol 1 in an enantioselective homo Diels-Alder reaction to yield the deltacyclene 2 with 92% ee. 2 was hydrogenated stereoselectively to give the enantiomerically pure, deltacyclane-based tertiary alcohol 3, a candidate for conversion into an optically active hydroperoxide for enantioselective oxidation reactions.
The optimal forming conditions of terbium chelate with trimesic acid in the presence of beta-cyclodextrin have been investigated. A simple, rapid, sensitive and selective method for the fluorimetric determination of terbium has been developed. The reaction is carried out at pH 4.80 similar to 5.20 in aqueous medium. A linear range of terbium concentration of 2.08 x 10(-5) similar to 4.00 x 10(-8) mol l(-1) is obeyed with a detection limit of 1.0 x 10(-8) mol l(-1) and a standard deviation of +/- 1.1%. The interference was also studied. Synthetic solutions are prepared according to some international standard reference rocks, which are composed of known amounts of the rare earth elements in addition to calcium, aluminium, iron and so on. And terbium is determined using the proposed method.
