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1.
研究了l-肼基-2,3-二氮杂萘盐酸盐的合成新方法.以相对廉价易得的邻苯二甲酸酐为起始原料,依次通过还原、溴代、环合、取代、酸化等反应步骤得到目标产物1-肼基-2,3-二氮杂萘盐酸盐.研究表明该方法具有原料便宜易得、收率高、产物易分离纯化、后处理操作简单、总成本低等优点. 相似文献
2.
Giomi D Alfini R Micoli A Calamai E Faggi C Brandi A 《The Journal of organic chemistry》2011,76(22):9536-9541
1-(2-Pyridyl)-2-propen-1-ol, obtained by vinylation of commercially available picolinaldehyde, resulted a good starting material for the synthesis of the indolizidine skeleton. In particular, a simple process involving bromination, reduction, and nucleophilic substitution (via elimination and addition) allowed an easy conversion of the starting material into (±)-lentiginosine in ~27% overall yield. 相似文献
3.
A three-step synthesis towards 1-aminomethyl-1-fluorocycloalkanes was developed starting from methylenecycloalkanes. Methylenecyclobutane, methylenecyclopentane and methylenecyclohexane were first bromofluorinated to provide the corresponding Markovnikov products, 1-bromomethyl-1-fluorocycloalkanes, which were then converted towards the title compound via azide substitution and hydrogenation. The bromofluorination of methylenecyclopropane, however, led to both the Markovnikov and the anti-Markovnikov product. 相似文献
4.
Reactions of 1-alkynyl-1-chlorocyclopropanes with lithium dialkylamides gave previously unknown 1-alkynyl-2-dialkylaminocyclopropanes.
1-(Alk-1-ynyl)-2-diazolylcyclopropanes were obtained by reactions of 1-alkynyl-1-chlorocyclopropanes with diazoles in the
presence of KOH in DMSO at 100 °C. These reactions passed through the formation of conjugated alky-nylcyclopropenes and reversible
addition of amide anions to them. The regioselectivity and stereoselectivity of these transformations depend on the substituents
in the starting chlorocyclopropanes and amines. 相似文献
5.
Helene Wolleb Francesco Bonina Megan Udry Stefan Reber Nicole Blumer Daniel Leuenberger Gabriel Schäfer 《Helvetica chimica acta》2023,106(10):e202300124
An efficient three-step synthesis of (1R)-1-(4-bromophenyl)-2,2,2-trifluoroethan-1-amine hydrochloride ( 1 ) starting from inexpensive and readily available starting materials was developed. The sequence features a highly diastereoselective trifluoromethylation of a chiral sulfinimine using the Rupert–Prakash reagent TMSCF3 in combination with K3PO4 as an initiator. The diastereomeric purity of the resulting sulfinamide was further improved by direct precipitation of the desired diastereomer from the reaction mixture upon addition of water. The chiral auxiliary was then removed under acidic conditions, resulting in the isolation of chiral benzylamine 1 as its hydrochloride salt in 71 % overall yield and excellent purity (LC/MS: >99 % a/a; e.r.=99 : 1). 相似文献
6.
《Tetrahedron letters》1987,28(26):3035-3038
N-Benzyl-2-carboxy-2-deoxypento and hexopyranosylaminolactams readily available via addition of trichloroacetyl isocyanate to substituted glycals, were transformed into enantiomerically pure N-benzyl-4-alkoxy-3-hydroxymethylazetidinones-2. The transformation involved the glycolic cleavage which was followed by sodium borohydride reduction. The above compounds can serve as starting materials for the synthesis of 1-oxapenams and 1-oxacephems. 相似文献
7.
Synthesis of Isoquinoline-1, 3-Dicarboxylic Acid 总被引:3,自引:0,他引:3
Chiropticalluminescencemeasurementslhavebeenusedforstudyingchiralitydependentmolecularexcited-statedynamic,forstlldyingexcited-stateracemizationkineticsassociatedwithintermolecularchiralrecognitionprocessesinsolution2.Intheseprocesses,therearetwomolecularspecies,lanthanidecomplexes(luminophore)andresolvedtransitioncomplexes(AorA,quencher).Manykindsoftransitionmetalcomplexeshavebeenusedasquencherstoinvestigateinfluenceoftheintermolecularchiralrecognition.However,theluminophoreswereonlyconfined… 相似文献
8.
《Tetrahedron》2013,69(19):3907-3912
A method for the regioselective synthesis of 3-unsubstituted 1-alkyl-1H-indazoles, starting with 2-halobenzonitriles and N-alkylhydrazines, is described. The two-step reaction pathway proceeds through the intermediacy of 1-alkyl-3-amino-1H-indazoles followed by reductive deamination. 相似文献
9.
Nieto RM Coelho A Martínez A Stefanachi A Sotelo E Raviña E 《Chemical & pharmaceutical bulletin》2003,51(9):1025-1028
A series of 6-methyl-1H-pyrimidin-2,4-diones bearing different substituents in the 1-position of the uracil ring were prepared starting from substituted ureas and diketene. 相似文献
10.
Two different approaches to the synthesis of 1-unsubstituted 5-cinnamoyl-3,4-dihydropyrimidine-2(1H)-ones have been developed. The first includes N(1)-protection of the starting 5-acetyl-3,4-dihydropyrimidine-2(1H)-one, further Claisen–Schmidt reaction, and cleavage of the protecting group. The second approach consists of one-pot condensation of urea, aldehyde, and cinnamoylacetone as dicarbonyl component. The 5-cinnamoylderivative synthesis starting from 5-acetyl-1,3-dialkyl-3,4-dihydropyrimidine-2(1H)-ones is also shown. 相似文献
11.
A new simple procedure for the synthesis of diastereomeric 1,2-diamino-1-phenylpropanes starting from u-N-trifluoroacetyl-2-amino-1-phenylpropan-1-ol (N-trifluoroacetylnorephedrine) is described. The trifluoroacetyl protecting group was particularly suitable for the protection of the amino group in order to reduce side reactions. 相似文献
12.
Ramakrishna Katakam Rajender Anugula Lingamurthy Macha Venkateswara Rao Batchu 《Tetrahedron letters》2017,58(6):559-562
A short and stereoselective synthesis of conduramine F-1 and ent-conduramine E-1 derivatives have been achieved starting from d-mannitol using nucleophilic vinylation on imine. A concise sequence of vinylation at both ends of d-mannitol and followed by RCM allowed us to prepare target compound. 相似文献
13.
F. Guerrera L. Salerno M. C. Sarv M. A. Siracusa 《Journal of heterocyclic chemistry》1995,32(2):591-594
The synthesis of novel 1-alkyl or 1-aryl-2-(4-substituted-1-piperazinyl)-1-H-benzothieno[2,3-d]imidazoles 7e-x starting from 2-nitro-3-bromobenzo[b]thiophene is described. These compounds were prepared as potential H1-antihistaminic agents. 相似文献
14.
Alexei AnikinMichael Maslov Joachim SielerSteffen Blaurock Jens BaldamusLothar Hennig Matthias FindeisenGerd Reinhardt Ramona OehmePeter Welzel 《Tetrahedron》2003,59(28):5295-5305
1α-Amino-1,6,9-trideoxy forskolin was synthesized starting from drimenal and an isoprenoid C5 unit. A tricyclic labdane with the entire forskolin skeleton was available in only four steps. Barton's nitrite photolysis was applied to functionalize C-1. 相似文献
15.
Dispersed fluorescence spectra following the excitation of the CBr2A1B1-X1A1 2 and 2 bands at visible wavelengths were acquired in a discharge supersonic free jet expansion using an intensified charge-coupled device (ICCD) detector. The dispersed fluorescence spectra show signal-to-noise ratios of up to 60 and extend out to a maximum red shift frequency of 6000 cm(-1). Complete and detailed vibrational structure of the ground singlet state (X1A1) was observed. Vibrational parameters including fundamental frequencies, anharmonicities, and coupling constants were determined for the CBr2 X1A1 state. Additional vibrational structure starting at approximately 3650 cm(-1) was observed and this indicates the singlet-triplet energy gap to be >10 kcal mol(-1). 相似文献
16.
《合成通讯》2013,43(24):4241-4252
Abstract New N-substituted 7-amino-1-nitro-2-heptanone derivatives have been obtained starting from readily accessible 2-(nitromethylidene)hexahydro-1H-azepine. These compounds have been further used as starting materials for the synthesis of some heterocycles with 5-aminopentyl fragment. 相似文献
17.
Verma SK Nguyen QH MacDougall JM Fleischer EB Moore HW 《The Journal of organic chemistry》2000,65(11):3379-3386
6-exo-Methylbicyclo[3.2.0]hepten-7-ones and their 2-alkylidene analogues are readily prepared from dialkyl squarates. These compounds undergo facial oxy-Cope ring expansions upon treatment with vinyllithium; the former leads to bicyclo[4.2. 1]non-1(4)-en-6-ones and the latter to the first examples of bicyclo[5.2.1]dec-1(10)-en-5-ones, compounds having exceptionally strained bridgehead double bonds. The transformations are controlled by the 6-exo-methyl group in the starting material along with the substituent at position-1 (bridgehead) which force attack of the lithium reagent from the concave face of the starting material, thus allowing the cyclopentenyl or alkylidene groups to participate in the sigmatropic event. 相似文献
18.
Zhang Dawei Ren Lu Liu Ailing Zhang Yumin Lv Yang Gu Qiang 《Research on Chemical Intermediates》2022,48(3):983-1001
Research on Chemical Intermediates - An efficient synthesis of 1,3,5-trisubstituted-1H-pyrazoles was developed via cyclocondensation in 78–92% yields starting from α,β-unsaturated... 相似文献
19.
20.
The intermolecular Diels-Alder reactions of several furans with α-chloroacrylonitrile occurs at atmospheric pressure. The role of temperature in affecting starting material: product ratio is examined from a preparative viewpoint. 相似文献