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1.
Tian-Bao Huang Ling-Fei Liu Xiao-Ming Yu Wen-Qian Yang Xu-Hong Qian Jingling Zhang 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):307-312
Abstract Three pathways were observed in the reactions of Schiff bases of Thiohydrazides with P(NR2)3. (a) MeS-R2N exchange: MeS-C([dbnd]S)-NHN[dbnd]CHPh (1) reacted with P(NR2)3 led to new Schiff bases, R2N-C([dbnd]S)-NHN[dbnd]CH = Ph (2). (b) Cleavage of C[dbnd]S bond and the formation of P[dbnd]S bond: H2N-C([dbnd]S)-NHN[dbnd]CH = Ph (3) reacted with P(NR2)3 gave rise to the thiophosphoric amide. (Et2N)2P([dbnd]S)-NH-CH = N-N[dbnd]CH-Ph (4). (c) Formation of thiadiazole and triazole: Schiff bases 2a and H2N(MeS)C = N-N[dbnd]CH-Ph (6) reacted with P(NR2)3 respectively and produced 5-dimethylamino-2-phenyl-2,3-(2H)-1,3,4-thiadiazole (5) and 5-methylthio-2-phenyl-2,3-(2H)-1,3,4-triazole (7). 相似文献
2.
F. M. Soliman Kh. M. Khalil G. Abd-el-naim 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract The reaction of 1,2-benzo [a] phenazine-8, 9-dione 1 and/or 1,2,3-indantrione 2, with phosphonium ylides has been studied. When 1 was reacted with two molar amounts of methoxy-(3a) and/or ethoxycarbonylmethylenetriphenylphosphorane (3b), in THF, at the reflux temp, for 3 hrs, dimethyl (4a) and/or diethyl 1,2-dihydrobenzo a furo [3,2-h] phenazine-1,2-dicarboxylate (4b), along with triphenylphosphine oxide and triphenylphosphine were obtained. On the other hand, reaction of equimolar amounts of ylides 3 with the red trione 2 in THF at room temp., afforded colourless crys tals of 2′,4′-dihydroxyspiro [indan-2,3′ (2′H)-indeno [1,2-b] pyran]-1,3,5′(4′H)-trione diacetate (5a) or dipropionate (5b), together with triphenylphosphine oxide. Formation of 6-membered dihydro aromatic ring like 5, is considered as a new reaction of phos phoranes. The structure of the new compounds 4 and 5 was confirmed and the reaction mechanisms are discussed. 相似文献
3.
A useful synthesis of 3-hydroxy-4-chromanone (6) is not currently available. Lead tetraacetate oxidation of 4-chromanone (4) yields the C(3) acetoxy derivative but this compound could not be deacetylated to 6.1 Recently Donnelly and Maloney reported2 that the Algar-Flynn-Oyamada reaction (H2O2/CH3OH/NaOH), which is commonly used for the conversion of o-hydroxychalcones (1) into 3-hydroxyflavanone (2) and 3-hydroxyflavones (3), does not yield 6 when applied to o-hydroxya-crylophenone 1 (R = H). The authors found that under less basic conditions using K2CO3 some 6 is formed but the major product is catechol. These observations clearly indicate the necessity of developing a method for making 6. The present note describes a staightforward way of preparing 3-hydroxy-4-chromanone (6) in good yield. 相似文献
4.
Annie Grouiller Bolenketa Nonga Marie-Line Navarro Patrick Molière Henri Pacheco 《Journal of carbohydrate chemistry》2013,32(3):507-524
Abstract Various 4-deoxy-α or β-erythro or threo-pentopyranoses aminated on position 1 [6 and 19]. 2 [38] or 3 [9, 22, 23, 24, 32 and 35] were synthesised from 2-methoxy-5,6-dihydro-2H-pyran [1] and methyl 2,3-anhydro-4-deoxy-α and β-DL-erythro-pentopyranoside [11]. Different reactions were investigated including azidation. cis-oxyamination, epimine formation and oxirane aminolysis. All these amino sugars were converted into their chloroethylureido derivatives. 相似文献
5.
Ana Calvo-mateo María-José Camarasa Angel Díaz-Ortíz Federico G. De las Heras Antonio Alemany 《Journal of carbohydrate chemistry》2013,32(3):395-404
Abstract Aldol reaction of 1,2-O-isopropylidene-5-O-tertbutyl-dimethylsilyl-α-D-erythro-pentofuranos-3-ulose (1) with acetone in the presence of aqueous K2CO3 afforded 3-C-acetonyl-1,2-O-isopropylidene-5-O-tertbutyl-dimethylsilyl-α-D-ribofuranose(2). Similar reaction of 1,2:5, 6-di-o-isopropylidene- α-D-ribo-hexofuranos-3-ulose (3) afforded 3-C-acetonyl-1,2:5, 6-di-o-isopropylidene- α-D-allofuranose (4) and (1R, 3R, 7R, 8S, 10R)-perhydro-8-hydroxy-5,5,10-trimethyl-2,4,6,11,14-pentaoxatetracyclo[8,3,1,01,8,03,7] tetradecane. The stereochemistry of the new chiral centers were determined by 1H NOE experiments. 相似文献
6.
N-(2-Bromoethyl)phthalimide (1) was reacted with sodium imidazolate in DMF to give the novel aminal N-[1-(1H-imidazol-1-yl)ethyl]phthalimide (4a) as well as N-vinylphthalimide (3) and the desired Gabriel intermediate 2. Aminal 4a as well as heterologues 4b - d form directly from reaction of 3 with the appropriate heterocyclic sodium salt. 相似文献
7.
Condensation reaction of 3,5-di-O-benzoyl-1,2-O-(1-cyanoben-zylidene)-β-D-arabinofuranose (2) with benzyl and allyl 2,3-di-O-benzoyl-5-O-triphenylmethyl-α-L-arabinofuranosides (5a and 5b) in methylene chloride in the presence of triphenylcarbenium tetrafluoroborate as catalyst under high vacuum gave α-(1→5)-linked dimeric D-arabinofuranoside derivatives (6a and 6b). One of the dimeric compounds (6a) was debenzoylated, triphenylmethylated, and rebenzoylated to give a dimeric homolog of 5a (8). Similarly for the preparation of 6a, 8 was condensed with 2 to provide an α-(1→5)-linked trimeric D-arabinofuranoside derivative (9). Further elongation of the glycoside chain might be possible in the same way. 相似文献
8.
6-Alkylpyrano [3,2-c] quinolin-5(2H)-ones(11a-e) were obtained in excellent yields by simply refluxing propynyl and butymyl ethers (6) of 4-hydroxy-1-alkylquinolin-2H-ones (2) in chlorobenzene for 10h, 5-Prop-2-ynyloxy-2H-pyrano [3,2-c] quinoline (12) was also obtained from the thermal rearrangement of 2,4-bis prop-2-ynyloxyquinoline (4). 相似文献
9.
C. K. Ghosh 《合成通讯》2013,43(7):487-490
For our synthetic work we needed the title compound. Literature survey revealed that 2-amino-4-oxo-4H-[1] benzopyran-3-carboxaldehyde (2-amino-3-formylchro-mone) can undergo condensation with diethyl malonate (or ethyl cyanoacetate) forming ethyl 2-hydroxy(or amino)-5-oxo-5H-[1]benzopyrano[2,3-b]pyridine-3-carboxylate1. 相似文献
10.
The reaction of 4,6-dinitrobenzofuroxan 1 with alkali metal salts of formanilides 2 affords 6′-nitrogen bonded Meisenheimer complexes 3 which upon heating in water form 4-arylamino-5, 7-dinitrobenzofurazans 5 in good lides in the presence of sodium hydroxide is also described. 相似文献
11.
Abstract The reaction of N-phenyliminoketenylidenetriphenylphosphorane [a] (1), with 2-benzylidene-1, 3-indandione (2), 1,2-diphenyl-3,4-pyrazolidenedione (3)and/or 5-benzylidene barbituric acid (4) has been investigated. When ylide 1 was allowed to react with compounds 2, 3 or 4 in THF at ambient temp. the corresponding new pyrano-phosphoranylidenes 5, 6 or 7 were obtained. The elemental microanalyses, IR, 1H NMR, 31P NMR and MS data agree with the structure of the cyclic iminophosphoranes by [4+2]-cycloaddition and exclude 4-membered ring structure by [2+2]-cycloaddition. When the Wittig reaction was carried on the pyrano-phosphoranes 5, 6 or 7 using p-nitrobenzaldehyde, the exocyclic olefins together with triphenylphosphine oxide were isolated. 相似文献
12.
A.V. Narender Reddy Samarendra N. Maiti Inder Pal Singh Ronald G. Micetich 《合成通讯》2013,43(17):3021-3025
Reaction of chlorosulfonyl isocyanate with nitroketene aminals of imidazolidines afforded acyclic intermediates which on treatment with diisopropylamine were smoothly transformed into the corresponding 1-substituted-1,2,3,7-tetrahydro-8-nitroimidazo [1,2-a] [1,2,6] thiadiazine-7 (1H) one-5, 5-dioxides. 相似文献
13.
The synthesis of 3-benzylpicolinic (5) and 3-benzylisonicotinic (6) acids via ionic reductive cleavage (HI/H3,PO2) of the aza-phthalides (3) and (4), is described. 相似文献
14.
G. Becker M. Mayer O. Mundt H. Riffel H. J. Wessely A. Simon 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract In (dimethylaminomethylidene)phosphines (1) [1] and -arsines (2) the internal rotation of the dimethylamino group is hindered by a barrier of 50 to 55 kJmol?1? analogous to the corresponding amidines. In order to evaluate the influence of this conjugative effect upon the P=C and (P)-C-N bond lengths, single crystal x-ray structure determinations of 1a and 2a have been carried out. For comparison, the cyclic (aminomethylidene)phosphine 1H-1,3-benzazaphosphole 5 [2] as well as the dimeric compounds 3a, 3b, and 3c [3] have been analyzed, too, while the arsenic derivative 6 was studied by others [4]. The diarsetanes 4 could not yet be isolated. The structural results indicate the E=C bonds in 1a, 2a, 5, and 6 to be scarcely elongated, the (E)-C-N bonds, however, to be shortened considerably with respect to the dimers. 相似文献
15.
S. D. Burton K. C. Kumara Swamy R. R. Holmes R. O. Day 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract New monoorgano-oxotin cages which possess bridging arsinate ligands have been prepared and characterized by X-ray and 119Sn NMR spectroscopy. The tetrameric, trimeric, and dimeric tin compounds containing arsinate ligands and six-and four-membered stannoxane rings exhibit characteristics which parallel the phosphinate-bridged cages previously reported.1,2 Conversion of the tetrameric cube structure, [n-BuSnO(O2AsMe2)]4, to a mixed butterfly composition is easily accomplished by addition of arsinic, phosphinic, or carboxylic acid. For example, two butterfly compounds that we formed are: [n-BuSn(OH)(O2AsMe2)(OP(O)Me2)]2 and [n-BuSn(OH)(02AsMe2)(OAs(O)Me2)]2. 相似文献
16.
A probable biogenetic type synthesis of coumestans by coupling in-situ generated o-quinones by mushroom tyrosinase oxidation of catechol and 4-hydroxy coumarins is reported. 相似文献
17.
Kin-Ichi Tadano Yuklaki Kameda Youichi Limura Tetsuo Suami 《Journal of carbohydrate chemistry》2013,32(2):231-244
Abstract Two optically active pseudo-hexopyranoses, pesudo-α-D-glucopyranose (1) and pseudo-β-L-altropyranose (2), were synthesized starting from L-arabinose. L-Arabinose was first converted to an acyclic aldehyde 9. The reaction of 9 with dimethyl malonate under basic conditions provided a tetra-hydroxylated cyclohexane-1,1-dicarboxylate 11 and a C-glycoside of β-L-arabinopyranose 12. From the compound 11, the desired two pseudo-sugars were synthesized by 1) thermal demethoxy-carbonylation, 2) LiAlH4, reduction, 3) hydroboration of the resulting 1-hydroxymethyl-l-cyclohexene 14 followed by hydrogen peroxide treatment, and 4) removal of the protecting groups. 相似文献
18.
James C. Goodwin 《Journal of carbohydrate chemistry》2013,32(2):255-263
Sodium bis(3-O-hydroxy-2-furyl methyl ketone) (3) and sodium 3-O-hydroxy-2-methyl-4-pyrone hydrate (4) were isolated and characterized from the interaction of isomaltol and maltol with sodium methoxide in boiling benzene (toluene or acetone). Elemental analyses of 3 furnished the formula C12H11NaO6, and this composition was confirmed by conversion to isomaltol O-benzoyl ester. 相似文献
19.
Fused cyclobutanone derivatives have been utilized as intermediates in a variety of synthetic schemes.1) We are investigating the synthesis and ring opening reactions of cyclobutanones fused to indoles, benzo[b]furans, and benzo[b]-thiophenes, in part with the hope of discovering a novel method for introduction of two carbon atoms to such heteroaromatic systems. In this communication the synthesis and Beckmann fission2) of the cyclobutanone derivatives fused to 1-benzoyl-indoles and benzo[b]thiophene are described. This provides a new entry into indole-2-acetonitriles3) and benzo[b]thiophene-2-acetonitrile.4) 相似文献
20.
Abstract Both anomers of methyl 1-thio-L-rhamnopyranosides were prepared through methylation of the corresponding isothiouronium salt. 2,3-0-Isopropylidene-, benzylidene-and the until now unknown diphenyl-methylene acetals were synthesized. Phase-transfer catalysed benzylation and LiA1H4-AlCl3-type hydrogenolysis of benzylidene acetals were used to obtain partially benzylated derivatives. Comparing the C NMR data of the synthesized compounds with those of their 0-glycoside analogues revealed that the 0→S exchanges at the anomeric centres caused drastic upfield shifts (~15 ppm) at C-1 and moderate downfield shifts at C-2 and C-5, as well. The chemical shift values of other carbons are not sensitive to the 0→S replacement. 相似文献