bluuebunny/crossref_metadata_2025 huggingface dataset:
Fezf1 is required for penetration of the basal lamina by olfactory axons to promote olfactory development
Authors: Watanabe Yasuhito , Inoue Kiyoshi , Okuyama‐Yamamoto Ayako , Nakai Nobuhiro , Nakatani Jin , Nibu Ken‐Ichi , Sato Naoko , Iiboshi Yasuhiko , Yusa Kosuke , Kondoh Gen , Takeda Junji , Terashima Toshio , Takumi Toru
Published: April 2009

In the development of the olfactory system, olfactory receptor neurons (ORNs) project their axons from the olfactory epithelium (OE) to the olfactory bulb (OB). The surface of the OB is covered by the central nervous system (CNS) basal lamina. To establish this connection, pioneer axons of the ORNs penetrate the CNS basal lamina at embryonic day 12.5 in mice. The importance of this penetration is highlighted by the Kallmann syndrome. However, little has been known about the molecular mechanism underlying this penetration process. Fezf1 (also called as Fez, Zfp312‐like, and 3110069A13Rik) is a C2H2‐type zinc‐finger gene expressed in the OE and hypothalamic region in mice. In Fezf1‐deficient mice, ORN axons (olfactory axons) do not reach the OB. Here we demonstrate that Fezf1‐deficient olfactory axons do not penetrate the CNS basal lamina in vivo, and the penetration activity of the axons in Matrigel is impaired in vitro. Coculture experiments using the OE and OB reveal that axonal projection of ORNs is rescued in Fezf1‐deficient mice in which the meninges including the CNS basal lamina are removed from the mutant OB. These data indicate that Fezf1 is required for the penetration of olfactory axons through the CNS basal lamina before they innervate the OB. J. Comp. Neurol. 515:565–584, 2009. © 2009 Wiley‐Liss, Inc.
Synaptic organization of the tectorecipient zone of the rat lateral posterior nucleus
Authors: Masterson Sean P. , Li Jianli , Bickford Martha E.
Published: April 2009

Dorsal thalamic nuclei have been categorized as either “first‐order” nuclei that gate the transfer of relatively unaltered signals from the periphery to the cortex or “higher order” nuclei that transfer signals from one cortical area to another. To classify the tectorecipient lateral posterior (LPN), we examined the synaptic organization of tracer‐labeled cortical and tectal terminals and terminals labeled with antibodies against the type 1 and type 2 vesicular glutamate transporters (vGLUT1 and vGLUT2) within the caudal/lateral LPN of the rat. For this zone, we found that all tracer‐labeled cortical terminals, as well as vGLUT1 antibody‐labeled terminals, are small profiles with round vesicles (RS profiles) that innervate small‐caliber dendrites. Tracer‐labeled tecto‐LPN terminals, as well as vGLUT2 antibody‐labeled terminals, were medium‐sized profiles with round vesicles (RM profiles). Tecto‐LPN terminals were significantly larger than cortico‐LPN terminals and contacted significantly larger dendrites. These results indicate that, within the tectorecipient zone of the rat LPN, cortical terminals are located distal to tectal terminals and that vGLUT1 and vGLUT2 antibodies may be used as markers for cortical and tectal terminals, respectively. Finally, comparisons of the synaptic patterns formed by tracer‐labeled terminals with those of vGLUT antibody‐labeled terminals suggest that individual LPN neurons receive input from multiple cortical and tectal axons. We suggest that the tectorecipient LPN constitutes a third category of thalamic nucleus (“second‐order”) that integrates convergent tectal and cortical inputs. This organization may function to signal the movement of novel or threatening objects moving across the visual field. J. Comp. Neurol. 515:647–663, 2009. © 2009 Wiley‐Liss, Inc.
Increase of intracellular Ca2+by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat
Authors: Fischer Wolfgang , Nörenberg Wolfgang , Franke Heike , Schaefer Michael , Illes Peter
Published: April 2009

The expression and functionality of P2X/P2Y receptor subtypes in multipolar nonpyramidal neurons of mixed cortical cell cultures were investigated by means of immunocytochemistry and fura‐2 microfluorimetry. The morphological studies revealed that most of the neurons are immunoreactive for GABA and express a range of P2X/P2Y receptors, predominantly of the P2X2,4,6and P2Y1,2subtypes. P2X1and P2X7receptor immunoreactivity (IR) was found on thin axon‐like processes and presynaptic structures, respectively. Application of ATP caused a small concentration‐dependent increase in intracellular Ca2+concentration ([Ca2+]i) in most investigated neurons, whereas only about the half of these cells responded to 2′,3′‐O‐(benzoyl‐4‐benzoyl)‐ATP (BzATP), ADPβS, 2MeSADP, or 2MeSATP and even fewer cells to UTP. In contrast, α,β‐meATP, UDP, and UDP‐glucose failed to produce any [Ca2+]isignaling. The response to ATP itself was inhibited by pyridoxal‐5′‐phosphate‐6‐azophenyl‐2′,4′‐disulfonic acid (PPADS), Reactive Blue 2, 2′‐deoxy‐N6‐methyl adenosine 3′,5′‐diphosphate (MRS2179), and suramin (300 μM) as well as by a cyclopiazonic acid‐induced depletion of intracellular Ca2+stores. A Ca2+‐free external medium tended to decrease the ATP‐induced [Ca2+]itransients, although this action did not reach statistical significance. Various blockers of voltage‐sensitive Ca2+channels and the gap junction inhibitor carbenoxolone did not interfere with the effect of ATP, whereas a combination of the ionotropic glutamate receptor antagonists D(–)‐2‐amino‐5‐phosphonopentanoic acid (AP5) and 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX) decreased it. Cross‐desensitization experiments between ADPβS or UTP and ATP suggested that ATP acts on the one hand via P2Y1,2receptors and on the other hand by additional signaling mechanisms. These mechanisms may involve the release of glutamate (which in consequence activates ionotropic glutamate receptors) and the entry of Ca2+via store‐operated Ca2+channels. Evidence for the presence of functional P2X receptors, in particular P2X7, remains elusive. J. Comp. Neurol. 516:343–359, 2009. © 2009 Wiley‐Liss, Inc.
Neuroanatomical plasticity in the gonadotropin‐releasing hormone system of the ewe: Seasonal variation in glutamatergic and γ‐aminobutyric acidergic afferents
Authors: Sergeeva Anna , Jansen Heiko T.
Published: April 2009

Temperate zone animals time the onset of reproductive events to coincide with specific portions of the sidereal year. Although the neural mechanisms involved remain poorly understood, a marked annual variation in the brain's sensitivity to estradiol negative feedback is thought to mediate many of the changes in neuroendocrine hormone secretion, especially that of the gonadotropin‐releasing hormone (GnRH) neurons, via neural afferents. The aim of the present study was to determine whether glutamatergic inputs to GnRH neurons in sheep vary seasonally and to expand our previous observations of seasonal changes in γ‐aminobutyric acid (GABA)‐ergic inputs. Brains from adult sheep were collected during the breeding season (N = 8) or the nonbreeding season (anestrus; N = 7). Confocal microscopy and optical sectioning were used to quantify the density of labeled VGLUT2 and VGAT immunoreactivity onto GnRH neurons. The results reveal a significantly greater number of VGLUT2‐ir inputs to GnRH dendrites during the breeding season vs. the nonbreeding season but no seasonal changes on GnRH cell somas. The number of VGAT‐ir terminals onto GnRH dendrites was reduced in the breeding season compared with the nonbreeding season. GnRH neurons were also found to receive dual‐phenotype (VGLUT + VGAT) inputs; these varied with season in a manner similar to VGAT inputs. Morphologically, the numbers of branches of proximal dendrites increased significantly in a subset of GnRH neurons located near the midline. Together these results reveal a dynamic seasonal reorganization of identified inputs onto GnRH neurons and lend additional support to the overall hypothesis that seasonal modulation of GnRH neurons involves glutamatergic and GABAergic neural plasticity. J. Comp. Neurol. 515:615–628, 2009. © 2009 Wiley‐Liss, Inc.
Database of queryable gene expression patterns for Xenopus
Authors: Gilchrist Michael J. , Christensen Mikkel B. , Bronchain Odile , Brunet Frédéric , Chesneau Albert , Fenger Ursula , Geach Timothy J. , Ironfield Holly V. , Kaya Ferdinand , Kricha Sadia , Lea Robert , Massé Karine , Néant Isabelle , Paillard Elodie , Parain Karine , Perron Muriel , Sinzelle Ludivine , Souopgui Jacob , Thuret Raphaël , Ymlahi‐Ouazzani Qods , Pollet Nicolas
Published: April 2009

The precise localization of gene expression within the developing embryo, and how it changes over time, is one of the most important sources of information for elucidating gene function. As a searchable resource, this information has up until now been largely inaccessible to the Xenopus community. Here, we present a new database of Xenopus gene expression patterns, queryable by specific location or region in the embryo. Pattern matching can be driven either from an existing in situ image, or from a user‐defined pattern based on development stage schematic diagrams. The data are derived from the work of a group of 21 Xenopus researchers over a period of 4 days. We used a novel, rapid manual annotation tool, XenMARK, which exploits the ability of the human brain to make the necessary distortions in transferring data from the in situ images to the standard schematic geometry. Developmental Dynamics 238:1379–1388, 2009. © 2009 Wiley‐Liss, Inc.
Characteristic analysis of resonant filter
Authors: Mitsutake Yoshio , Hirata Katsuhiro , Nakata Manabu , Ishihara Yoshiyuki , Todaka Toshiyuki
Published: April 2009

Usually, the resonant filter is composed of several resonators made of dielectric and metal, and is applied to high‐frequency bandpass filters (BPFs). Although a resonant filter has a simple structure, it is very difficult to obtain the optimal geometry experimentally, because its filter characteristic is greatly influenced by the material and the structure. This paper presents an analysis method for the high‐frequency resonant filter by using the method of moment (MoM). The computed characteristics of the resonant filter are in good agreement with the measured ones. Furthermore, the influences of design parameters of the filter on the characteristics are investigated. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 42–48, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10053
Development of microreactor array chip‐based measurement system for massively parallel analysis of enzymatic activity
Authors: Hosoi Yosuke , Akagi Takanori , Ichiki Takanori
Published: April 2009

Microarray chip technology such as DNA chips, peptide chips, and protein chips is one of the promising approaches for achieving high‐throughput screening (HTS) of biomolecule function since it has great advantages in feasibility of automated information processing due to one‐to‐one indexing between array position and molecular function as well as massively parallel sample analysis as a benefit of downsizing and large‐scale integration. Mostly, however, the function that can be evaluated by such microarray chips is limited to affinity of target molecules. In this paper, we propose a new HTS system and enzymatic activity based on microreactor array chip technology. A prototype of the automated and massively parallel measurement system for fluorometric assay of enzymatic reactions was developed by the combination of microreactor array chips and a highly sensitive fluorescence microscope. Design strategy of microreactor array chips and an optical measurement platform for the high‐throughput enzyme assay are discussed. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 35–41, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10056
Regeneration‐type nerve electrode using bundled microfluidic channels
Authors: Suzuki Takafumi , Kotake Naoki , Mabuchi Kunihiko , Takeuchi Shoji
Published: April 2009

Neural interface devices that will allow signals from the human nervous system to control external equipment are extremely important for the next generation of prosthetic systems. A novel multichannel regeneration‐type nerve electrode designed to record from and stimulate peripheral nerves has been developed to allow the control of artificial hands and to generate artificial sensations. In this study a novel flexible regeneration microelectrode based on the nerve regeneration principle was designed and fabricated using MEMS technologies. The electrode, which was fabricated on a 25‐µm‐thick parylene C substrate, has multiple fluidic channels. Each fluidic channel was 100µm wide×30µm high×1500µm long and featured multiple electrodes inside them as recording and stimulating sites. They also served as guidance channels for the regenerating axons. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 29–34, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10059
An algorithm for detecting the center of the iris using a color image and improvement of its processing speed
Authors: Yonezawa Tetsuya , Ogata Kohichi , Shiratani Kazuyuki
Published: April 2009

We have studied a man–machine interface system by using an eye gaze detection technique. Target users for this system are ordinary people and orthopedically impaired people who have no movement in their hands and head. Ordinary people can use this system under the condition that they do not move their head. An algorithm for detecting the center of the iris is proposed in this paper. An image of the eye is captured with a small video camera and the center of the iris is obtained by filtering in color space and pattern matching with a ring‐shaped template. Improvement of the pattern matching speed is also described and the effectiveness of the reduction of calculation costs is shown. Furthermore, the accuracy of the eye gaze detection was evaluated. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 1–8, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10088
A low‐power droplet manipulator employing high‐frequency surface acoustic waves
Authors: Sasaki Tsutomu , Tanaka Yasutomo , Omori Tatsuya , Hashimoto Ken‐Ya , Yamaguchi Masatsune
Published: April 2009

A droplet manipulator working with low driving power was developed by using the surface acoustic wave (SAW) technology. The manipulator was driven at a relatively high frequency of 350 MHz to increase the SAW power density. First, a single‐phase unidirectional transducer (SPUDT) was designed. Because of its low insertion loss of 1.5 dB and high directivity of 10 dB, the SPUDT successfully conveyed a 100‐nl water droplet with RF input power of 18 dBm (60 mW). Second, the SPUDT design was extended to a curved transducer to focus and launch the SAW energy into the narrow waveguide. Owing to the increased SAW power density, the required SAW power was reduced to 15 dBm (30 mW) for the 100‐nl droplet manipulation. In addition, fabrication of liquid injectors was discussed for the formation of tiny droplets. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 49–55, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10232
Combined Extraction and Electrochemical Detection of Amines and Phenols Using Microelectrodes in Organic Solvents
Authors: Mathiyarasu Jayaraman , Nyholm Leif
Published: April 2009

A straightforward approach for liquid‐liquid extractive detection of aromatic amines and phenols is described based on the spontaneous transfer of the molecule from the aqueous to an organic phase and subsequent electrochemical detection in the latter phase using a microelectrode. It is demonstrated that the extent of the transfer can be modified by altering the pH of the aqueous solution and the organic solvent. It is also concluded that the presence of an ion‐pair formation agent does not increase the transfer yield for 4‐chloroaniline and phenol. The present approach combines liquid‐liquid sample clean‐up and quantification into a single step which significantly facilitates determinations of aromatic amines and phenols present in complex samples.
Semiparametric penalized generalized additive models for environmental research and epidemiology
Authors: Schimek Michael G.
Published: April 2009

For more than a decade generalized additive models (GAMs) have been successfully applied in various environmental studies, for instance to evaluate the impact of air pollution on health. The air pollution measure is usually connected with the health indicator in a parametric fashion whilst the effects of other covariates are modelled through nonparametric smooth functions. This is the motivation for the widely used semiparametric GAMs. The backfitting‐GAM methodology, and its popular implementation in S‐Plus, constitutes the standard approach. Here we consider its limitations and offer an alternative penalized likelihood concept. The primary limitations are the lack of tools for multiple data‐driven smoothing parameter choice, slow convergence of the iterative backfitting algorithm when concurvity is present, and unstable biased estimates of the regression coefficients and their standard errors in the semiparametric case, even more pronounced under concurvity. The penalized likelihood methodology when combined with cubic spline smoothers allows for a computationally efficient and complete parametric representation of a GAM, either nonparametric or semiparametric. It helps circumvent most of the mentioned GAM flaws in environmental research and epidemiology (e.g. in studies of human exposure to particulate matter). Finally, we discuss various evidence from simulation experiments in the literature, concerning the proper use of the GAM methodology. Copyright © 2009 John Wiley & Sons, Ltd.
Parallel interference cancellation in DS‐CDMA optical networks using bias compensation
Authors: Okassa‐M'foubat A. , Dayoub I. , Rouvaen J. M. , Zouine Y.
Published: April 2009

A receiver based on the parallel cancellation of multiple access interference by bias compensation is considered here for a direct sequence unipolar optical code division multiple access (DS‐OCDMA) system. It relies on the estimation of interferences from undesired users, the regeneration of interfering signals at the output of first canceller stage and their substraction from the received signal after amplification by a bias compensation factor in the second stage. The performance of such a technique is analysed in a synchronous network using orthogonal optical codes and the results are compared with those for different types of conventional receivers. Copyright © 2009 John Wiley & Sons, Ltd.
Correlates of depressive symptoms in rural elderly Chinese
Authors: Gao Sujuan , Jin Yinlong , Unverzagt Frederick W. , Liang Chaoke , Hall Kathleen S. , Ma Feng , Murrell Jill R. , Cheng Yibin , Matesan Janetta , Li Ping , Bian Jianchao , Hendrie Hugh C.
Published: April 2009

Objective

Late life depression has been studied in many populations around the world. However, findings on risk factors for late life depression have remained inconsistent.

Methods

A cross‐sectional survey of 1737 rural Chinese age 65 and over from two provinces in China was conducted assessing cognitive functions using various cognitive instruments and collecting information on demographic characteristics and medical history. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS). Analysis of covariance and logistic regression models were used to identify factors associated with the continuous GDS score, mild or severe depression.

Results

In this cohort, 26.5% (95% CI: 24.4–28.6%) met the criteria for mild depression and 4.3% (95% CI: 3.4–5.4%) for severely depression. Living alone, history of heart attack, head injury, and fracture were associated with higher depressive symptoms. Alcohol consumption and higher cognitive function were associated with lower depressive symptoms. Living alone, not attended school, history of head injury, fracture, and low cognitive function were associated with increased probability of mild depression. Living alone, history of stroke or heart attack, and low cognitive function were associated with severe depression.

Conclusions

Depression, particularly mild depression, is common in rural elderly Chinese. Among a number of factors identified in this cohort as being significantly associated with depressive symptoms, living alone and lower cognitive function were the most consistent factors associated with depressive symptoms, mild and severe depression. History of stroke, heart attack, and fracture were also risk factors for depressive symptoms. Copyright © 2009 John Wiley & Sons, Ltd.
Stem cell exhaustion and leukemogenesis
Authors: Jacob Bindya , Osato Motomi
Published: April 2009

Cancer is the result of a combination of genetic alterations, which aid transformation of cells. However, oncogenic alterations also simultaneously induce some detrimental effects on the cells such as apoptosis, senescence, and differentiation. Such negative effects caused by certain oncogenic events are overcome by other cooperating genetic hits. We propose stem cell exhaustion as a novel detrimental effect that is caused by a wide variety of oncogenic alterations. Interestingly, in most cases, the stem cell exhaustion due to oncogenic alterations is preceded by an abnormal expansion of stem/progenitor cells. This preceding stem/progenitor cell expansion may be a key feature that still promotes cancer development, along with cooperating hits that rescue stem cell exhaustion. This review summarizes current knowledge about hematopoietic stem cell exhaustion and the mechanisms to overcome stem cell exhaustion in cancer development. J. Cell. Biochem. 107: 393–399, 2009. © 2009 Wiley‐Liss, Inc.
Pax‐6 is expressed early in the differentiation of a corneal epithelial model system
Authors: García‐Villegas Refugio , Escamilla Juan , Sánchez‐Guzmán Erika , Pastén Angela , Hernández‐Quintero Miriam , Gómez‐Flores Eber , Castro‐Muñozledo Federico
Published: April 2009

Pax‐6 is a regulatory gene with a major role during visual system development, but its association with corneal epithelial differentiation is not clearly established. Using the RCE1‐(5T5) cell line, which mimics corneal epithelial differentiation, we analyzed Pax‐6 biological role. Immunostaining of proliferating colonies and confluent sheets showed that Pax‐6‐positive cells were also K3 keratin‐positive, suggesting that Pax‐6 is expressed in differentiating cells. Pax‐6 mRNA was barely expressed in early cell cultures; but after confluence, its levels raised up to fivefold as demonstrated by Northern blot and RT‐qPCR. The raise in Pax‐6 expression preceded for 9 h the increase in LDH‐H and LDH‐M mRNAs, previously shown as early markers of corneal epithelial cell differentiation. The full‐length mRNAs encoding for the two major Pax‐6 isoforms were found at very low levels in proliferating cells, and abundantly expressed in the confluent stratified epithelia; Pax‐6 mRNA was 2‐ to 2.5‐fold more abundant than Pax‐6(5a) mRNA. The ectopic expression of Pax‐6 or Pax‐6(5a) decreased proliferative ability leading to the formation of abortive, non‐proliferative colonies. In contrast, culture conditions that delay or block corneal epithelial cell differentiation reduced or inhibited the expression of Pax‐6. Collectively, results show that Pax‐6 is the earlier differentiation marker expressed by corneal epithelial cells, and open the possibility for a major role of Pax‐6 as the main driver of the differentiation of corneal epithelial cells. J. Cell. Physiol. 220: 348–356, 2009. © 2009 Wiley‐Liss, Inc.
Impaired integrin‐mediated adhesion contributes to reduced barrier properties in VASP‐deficient microvascular endothelium
Authors: Schlegel Nicolas , Waschke Jens
Published: April 2009

Recent studies point to a significant role of vasodilator‐stimulated phosphoprotein (VASP) in the maintenance of endothelial barrier functions in vivo and in vitro. Moreover, it has been reported that VASP is required for activation of the small GTPase Rac 1. However, little is known whether VASP is involved in the regulation of cell adhesion molecules that are critical for maintenance of the endothelial barrier. Here we demonstrate that impaired barrier properties in VASP‐deficient (VASP−/−) microvascular myocardial endothelial cells (MyEnd) correlated with both impaired integrin‐mediated adhesion as revealed by laser tweezer trapping and reduced integrin‐dependent cell migration. This was paralleled by reduction of focal adhesions at the cell periphery as well as of β1‐integrin and VE‐cadherin cytoskeletal anchorage. Incubation of MyEnd VASP wt with RGD peptide to block interaction of integrins with extracellular matrix (ECM) reduced barrier properties and Rac 1 activity in wt endothelial monolayers mimicking the situation in VASP (−/−) cells under resting conditions. Moreover, cAMP‐mediated Rac 1 activation was reduced under conditions of impaired integrin‐mediated adhesion in wt cells and cAMP‐induced increase in VE‐cadherin cytoskeletal anchorage was abolished in VASP (−/−) endothelium. In summary, these data indicate that VASP is required for integrin‐mediated adhesion which stabilizes endothelial barrier properties at least in part by facilitating Rac 1 activation. J. Cell. Physiol. 220: 357–366, 2009. © 2009 Wiley‐Liss, Inc.
The synthesis and chelation properties of the oximes of certain pyridinyl‐ and diazinylmethyl ketones
Authors: Case Francis H. , Schilt A. A.
Published: April 2009

Two series of oximes derived from pyridinyl and diazinylmethyl ketones have been prepared and tested with regard to their metal‐chelation properties.
Synthesis of oxirnes. IV. 2‐pyridinealdoxime methiodides from 2‐picoline methiodides
Authors: Markovac Anica , Ash Arthur B. , Stevens Calvin L. , Hackley Brennie E. , Steinberg George M.
Published: April 2009

The Ortoleva‐King‐Krohnke sequence was used to prepare substituted 2‐pyridinealdoxime methiodides. The methodology was extended to prepare three analogs in which two molecules of 5‐hydroxy‐2‐pyridinealdoxime methiodide were coupled through the 5‐position with dihalides.
Diazo‐, Azo‐, and Azidoazoles. IV. Influence of substituents on the 2‐azidoimidazole/imidazo[1,2‐d]tetrazole equilibrium
Authors: Rull Montserrat , Vilarrasa Jaume
Published: April 2009

The effect of various common groups on the equilibrium 3 ⇌ 4 is discussed based on the Hammett substituent constants and the values of field and resonance constants calculated by Hansch, et al. N‐Chloroacetyl, dichloroacetyl and trichloroacetyl derivatives of 2‐azidoimidazole were also prepared. The shifting of equilibrium to the tetrazole form does not depend on the whole electron‐attracting effect of a group, but it is mainly governed by its resonance electron‐withdrawing ability.
Synthesis of some sulfonium salts and ylides containing the isoxazole nucleus
Authors: Bravo Pierfrancesco , Gaviraghi Giovanni
Published: April 2009

Some dimethylisoxazolylmethylsulfonium salts and the corresponding ylides were synthetized and their chemical behaviour studied. Dimethylsullonium‐5‐isoxazolyl methylides (XIa,b) give 5‐isoxazolyloxiranes (XIIa,d) and XIII when allowed to react with carbonyl compounds. Ring opening products from these oxiranes are also reported.
New helerocyclic ring systems from α‐llydroxymethylenekelones. VIII. Polyuzasteroidal analogues of equilenin
Authors: Fravolini A. , Martani A. , Grandolini G. , Strappaghetti G.
Published: April 2009

Some 6, 15,16‐triazasteroidal analogues of Equilenin carrying a 7‐methyl substituent have been synthesized from 4‐methyl‐7‐methoxy‐10,11]‐dihydroisoxazolo[5,4‐i]phenanthridine (III).
Synthesis of 1,4,6,7‐tetrahydroimidazo[2,1‐c] [1,2,4] triazines
Authors: Eberle Marcel K. , Schirm Paul
Published: April 2009

From 2‐methylthioimidazoline and phenaeylbromides in DMF there were obtained the 2‐(2‐methylthio‐2‐imidazolin‐1‐yl)aeetopht'nones 3a‐3f. From these the substituted 3‐phenyl‐1,4,6,7‐tetrahytlroimidazo[2,1‐c][1,2,4]triazines 4a‐4n were prepared upon reaction with hydrazine and methylhydrazine respectively. Compound 4a was degraded to the triazine 6. From the (2‐methylthio‐2‐imidazolin‐l‐yl)‐acetie acid ester 10, the imidazo[2,1‐c] [1,2,4]triazines 11a‐11c were prepared. Selective ethylation on the oxygen was achieved with 11b in the presence of Meerwein' salt.
Synthesis of 4‐(4‐phenyl‐3‐pyrazolyl)‐4H‐1,2,4‐triazoles
Authors: Lang S. A. , Lovell F. M. , Cohen E.
Published: April 2009

4‐(4‐PhenyI‐3‐pyrazolyl)‐4H‐1,2,4‐triazoles and 4‐phenyl‐5‐(4H‐1,2,4‐triazol4‐yl)‐3‐pyrazolols were prepared by the reaction of formylhydrazine on α‐phenyl‐α‐cyanoacetaldehydes and ethyl α‐phenyl‐α‐cyanoacetates.
Muss spectral fragmentation pattern of 2,2′‐bipyridyis. Part VI. 2,2′‐ thiodipyridine
Authors: Keats N. G. , Summers L. A.
Published: April 2009

The mass spectral fragmentation of 2,2′‐thiodipyridine is reported. The base peak is due to the MI ion. The principal fragmentation routes involve loss of H, CS, CHCS and HCN from the molecular ion and CS, HCN and S from the. M‐I species. Rupture of the central bonds is also an important disintegration pathway.
The synthesis of nareielasie aldehyde and related lsocarbostyrils
Authors: Passannanti Salvatore , Paternostro Maria Pia , Piozzi Franco , Savona Giuseppe
Published: April 2009

The synthesis of several isoearboslyrils is reported, including lorrnyl derivatives at (1‐4, like nareiclasie aldehyde (I) and the homologous aldehyde (XV).
Studies on the synthesis of heterocyclie compounds. II. Synthesis of 2,2‐disubstituted‐1,3‐benzoxathioles
Authors: Cabiddu Salvatore , Ciuccatosta Felicetta , Cocco Maria Teresa , Loi Giuseppe , Secci Mario
Published: April 2009

The condensation of 2‐hydroxythiophenol (I) with acetylenic compounds (IIa‐g) or halo‐genated esters (IV, V, VIa and b) led to the synthesis of 2,2‐disubstituted‐1,3‐benzoxathioles (IIIa‐g). The structures of these compounds were established by elemental analysis and by ir and nmr spectra.
A new synthon in heterocycle synthesis
Authors: Sato M. , Stammer C. H.
Published: April 2009

A tetraehlorobenzodioxinone, prepared from 2‐phenyl‐4‐benzyl‐2‐oxazolin‐5‐one and o‐chloranil was found to react with clhanol to give the ester 6. This compound reacted readily with various bis‐nucleophiles to form five‐ and six‐membered helerocyclic compounds.
Synthesis of 3,3′ ‐methylenediisoxazoles
Authors: Auricchio S. , Ricca A. , De Pava O. Vajna
Published: April 2009

The synthesis of new 3,3′‐methylenediisoxazoles (III), from 1,3‐dichloromalondioxime (IX) and acetylenic compounds is reported. We have studied the transformation of the chloronitroso compound (VII), obtained from malondioxime (V) in ether with gaseous chlorine at −70°, into IX. It was found that this was possible only by heating a DIYISO solution. The characteristics of the compounds which are described are reported.
Alumina‐catalyzed condensation of 2‐methylquinoline with methanol
Authors: Klemm L. H. , Hurtling Ross
Published: April 2009

The alumina‐catalyzed reaction of 2‐methylquinoline with excess methanol at 500° produced a mixture of 2‐ethyl‐, 2‐isopropyl‐, and 2‐isopropenylquinolines in yields of 10%, 7%, and 2%, respectively. A mechanistic interpretation of this reaction is presented.
Synthesis of new fundamental heterocycles. Part VII. Synthesis of 2‐azaxanthene
Authors: Sliwa H. , Cordonnier C.
Published: April 2009

2‐Azaxanthone (5) has been conveniently prepared by condensation of the morpholine enamine of 1‐benzyl‐4‐piperidone witli salicylaldehyde followed by chromium trioxide oxidation and subsequent aromatization. Lithium aluminum hydride reduction of 5 afforded the new fundamental heterocycle 2‐azaxanlhene.
A new synthesis of fervenulin 4‐oxide
Authors: Ichiba Misuzu , Senga Keitaro , Nishigaki Sadao , Yoneda Fumio
Published: April 2009

The reaction of 1,3‐dimethyl‐6‐hydrazino‐5‐nitrosouracil (1) with Vilsmeier reagent (dimethylformamide‐phosphorus oxychloride) afforded fervenulin 4‐oxide (II) in good yield.
3‐Halo‐4‐imino‐2‐azetidinones via acykchloroformamidines
Authors: Brady William T. , Owens Robert A.
Published: April 2009

α‐Haloacid Halides react with carbodimides to yield acylchloroformamidines which upon treatment with trithylamine undergo conversion to 3‐halo4‐imino‐2‐azetidinones in good yiels. Two pathways are possible for this conversion and these are discussed.
A convenient synthetic route to 5,5′‐Disubstituted 2,2′‐Bipyridines
Authors: Whittle C. P.
Published: April 2009

Syntheses are described for a number of 5,5′‐disubstituted 2,2′‐bipyridines. In particular the benzidine analogue, (2,2′‐bipyridine]‐5,5′‐diamine and some of its derivatives have been prepared.
The effect of electron withdrawing croups on the stability of thiabenzenes
Authors: Pirelahi Hooshang , Abdoh Yahyo , Tavassoli Manoochehr
Published: April 2009

The reactions of p‐trifluoromethylphenyllithium with 2,4,6‐triarylthiopyrylium perehlorates (Ar = Ph, p‐CH3OC6H4, p‐NMe2C6H4) have been studied. The initially formed thiabenzenes were not slable enough to he isolated and rearranged readily to their corresponding 4‐(p‐tri‐fluoromethylphenyl)‐2,4,6‐triarylthiopyrans. The instability of the intermediate thiabenzenes reveals that, in contrast to the stabilization effect of the electron‐withdrawing p‐chloro‐ and pentalluorophcnyl groups attached to carbon atoms in sulfur ring, the electron‐withdrawing p‐lrilluoromethyl group on subsliluenls attached to sulfur decreases the stability of thiabenzenes.
Further studies on the structural determination of esters of 4‐Oxo‐4H‐1‐heiizopyran‐2‐carboxylic acids using the paramagnetic shift reagent eu(FOD)3
Authors: Cairns H. , Hunter D.
Published: April 2009

The effect of Eu(fod)3 on the signals of benzylic ruethvlene protons in the pmr spectra of 4‐oxo‐4H‐1‐benzopyran derivatives is described. Assignments were confirmed by decoupling experiments. The technique provides a method for distinguishing between structural isomers.
Reaction of ketenes with N,N‐Disubstituted 2‐Aminomethylenecyclo‐alkanones VI. Synthesis of N,N‐Disubstituted 4‐Amino‐3,4‐dihydro‐3,3‐dithioethyl‐5,6‐polyrnethylene‐α‐pyrones
Authors: Bargagna Alberto , Schenone Pietro , Cafaggi Sergio
Published: April 2009

The reaction of dithioethylketene, a new dithioalkylketene prepared in situ from dithio‐ethylacetyl chloride and triethylamine, with N,N‐disubstituted 2‐aminomethylenecycloalkanones gave the 1,4‐cycloadducts, namely N,N‐disubstituted 4‐amino‐3,4‐dihydro‐3,3‐dithioethyl‐5,6‐polymethylene‐α‐pyrones.
Régiospécificité et stéréosélectivité de la cycloaddition de l'oxyde de benzonitrile sur les pyrazolines‐3
Authors: Cibert J.‐P. , Pétrus C. , Pétrus F.
Published: April 2009

La régiospécificité et la stéréosélectivilé de la cycloaddition de l'oxyde de benzonitrile sur les pyrazolines‐3 sont dérnontrées. L'étude du comportement en milieu acide des différentes pyrazolidino[4,3‐d]isoxazolines‐2 obtenues est réalisée et les processus d'épimirisation et de dégradation observés sont discutés en fonction du substituant en 4 et du solvant utilisé.
Oxidation of fully substituted alkoxyoxazolcs with singlet molecular oxygen
Authors: Graziano M. L. , Iesce M. R. , Carotenulo A. , Scarpati R.
Published: April 2009

Diacylcurbamatcs IV can be prepared from alkoxyoxazoles 1 by 1O2 oxidation. When the reaction is opportunely earried out a new heterocyclic system, namely the 3H‐1, 2, 4‐dioxazole III, is formed. A mechanistic interpretation of the results is suggested.
The reaction of β‐aminoaleohols with o‐Phthalaldehyde
Authors: Shipchandler M. T.
Published: April 2009

The reaction of o‐phthalaldehyde with β‐aminomonohydroxy compounds leads to ortho‐substituled phenyloxazolines. β‐Aminodiols or‐triols give tetracyelic bisoxazoiidines when reacted with o‐phthalaldchyde. These two type of ring systems are generated in one step under extremely mild conditions.
Studies on the oeearboxylation reactions. Note II. Kinetic study of the decarboxylation reaction of 5‐amino‐1,3,4‐thiadiazole‐2‐carboxylic acid (I) to 2‐amino‐1,3,4‐thiadiazole (III)
Authors: Spinelli Domenico , Noto Renato , Consiglio Giovanni , Buccheri Francesco
Published: April 2009

The rate constants of the deearboxylation reaction in water of 5‐amino‐1,3,4‐lhiadiazole‐2‐carboxylic acid (I) to 2‐amino‐1,3,4‐thiadiazole (III) over the pH range O.25‐3.91 have been measured and the activation parameters determined. The results obtained have been compared with previous results on the deearboxylalion of 5‐amino‐1,3,4‐oxadiazole‐2‐earboxylic acid (II) to gain information on the mechanism of the reaction studied.
Ozonolysis of 3,4‐dehydroproline
Authors: Nair V. , Kim K. H. , Walsh R. H.
Published: April 2009

Ozonolysis of protected 3,4‐dehydro‐DL‐proline (2) in methanol gives as the initially isolable product, a seven‐membered ring cyclic peroxide (5). Compound 5 undergoes rearrangement thermally to give methyl N‐tosylglycinate (8) and a stereochemical mixture of oxazolidine aldehyde esters (7). Structural evidence for 7 came from detailed 13C nmr studies of 7 and its reduction product (9).
Alkylation d'anions ambidents en catalyse par transfert de phase. Cas des hydroxypyridines
Authors: Dou Henri J.‐M. , Hassanaly Parina , Metzger Jacques
Published: April 2009

L'alkylation d'ions ambidents dérivés de la 2‐ et 4‐pyridones en catalyse par transfert de phase, conduit à 80% de N‐substitution et 20% de O‐substitution. Les changements de temperature, solvants, sels, halogénures d'alkyle, n'introduisent que de faibles variations dans le pour‐centage de N‐ et O‐ alkylation. Les rendements globaux varient entre 40 et 80% pour les halogénures d'alkyle primaires et secondaires.
Synthesis of some 3‐Hydroxy‐5‐pyridylpyrrole derivatives
Authors: Campaigne E. , Shutske G. M. , Payne John C.
Published: April 2009

Ethyl sarcosinate adds to 2, −3‐ and 4‐pyridylmethylidenemalonates to produce the Michael adducts, which can be conveniently cyclized to oxopyrrolidine diesters under Dieckmann conditions. Mild oxidation converted the crude adducts to the isomeric 1‐methyl‐3‐hydroxy‐5‐pyridylpyrrole‐2,4‐dicarboxylates. Addition of ethyl glycinate to ethyl picolinoylacetate or ethyl nicotinoylacetate produced the corresponding enaminoesters, but these azadiesters were not cyclized under the usual Dieckmann conditions.
Fused s‐triazino heterocycles. V. 1,3,4,6,9b‐Pentaazaphenalenes. Reactions of a carboxylic acid side chain
Authors: Shaw John T. , Miller Deborah A. , Holodnak J. Larry
Published: April 2009

Procedures were developed to convert 4‐(2‐methyl‐1,3,4,6,9b‐pentaazaphenalene‐5‐yl)butanoic acid (Ia) and 3‐(2‐methyl‐1,3,4,6,9b‐pentaazaphenalene‐5‐yl)propanoic acid (IIa) to a series of esters and amides.
Synthèse de nouveaux composés hétérocycliques: Les diaza‐4,5 pyrène, diaza‐4,5 pyrène‐4 N‐oxyde et diaza‐4,9 pyrène‐4,9 di N‐oxyde
Authors: Mugnier Y. , Laviron E.
Published: April 2009

Le diaza‐4,5 pyrène a été obtenu par cyclisation électrochimique à partir du dinitro‐4,5 phénanthrène, lui‐měme préparé par cyclisation du dinitro‐2,2′ diformyl‐6,6′ bipliényle. La cyclisation électrochimique de ce dernier composé conduit au diaza‐4,9 pyrène‐4,9 di N‐oxyde.
Catalytic desulfurization of condensed thiophenes by means of methanol
Authors: Klemm L. H. , Karchesy Joseph J.
Published: April 2009

Desulfurization of dibenzothiophene, two methyldibenzothiophenes, and phenanthro[4,5‐bcd]‐thiophene to give 60‐80% yields of hydrocarbon products was effected by means of a sulfided molydena catalyst plus methanol at 450° and a pressure of ca. one atmosphere. The methanol functions both as an in situ hydrogen donor and as a methylating agent.
Synthesis of substituted 2‐amino‐3‐cyano‐4‐methylpyrroles
Authors: Johnson Ronald W. , Matlson Ronald J. , Sowell J. Walter
Published: April 2009

A facile route for the synthesis of substituted 2‐amino‐3‐cyano‐4‐methylpyrroles fromN‐acetyl‐α‐amino ketones and malononitrile is reported.
A single crystal X‐Ray diffraction analysis of 1,9‐dihydro[1] benzothiopyrano[4,3‐c] pyrazole 5,5‐dioxide
Authors: Ealick Steven E. , Van Der Helm Dick , Ramalingam K. , Thyvelikakath George X. , Berlin K. D.
Published: April 2009

The structure of 1,4‐rlihydro[1 ]benzothiopyrano[4,3‐c ]pyrazole 5,5‐dioxide was determined by single crystal x‐ray diffraction. The molecule crystallizes in space group P21/c with a = 13.4378(6), b = 5.5938(3), c = 12.9837(6)Å, and β = 103.831°. The final R value is 0.083. Surprisingly, the tautomer with N(2)‐H exists in the crystal with the pyrazole ring being planar. The entire system is not planar as the benzene ring is rotated about C(9a) and C(9b) with respect to the pyrazole ring. In the crystal structure the pyrazole exists as hydrogen‐bonded dimers with two molecules related by a center of symmetry.
Synthesis of 7‐amirio‐2H, 4H‐vic‐triazolo[4,5‐c]‐[1,2,6]thiadiazine 5,5‐dioxides
Authors: García‐Muñoz C. , Ochoa C. , Stud M. , Pfleiderer W.
Published: April 2009

7‐Amino‐2H,4H‐vic‐triazolo[4,5‐c][1,2,6]thiadiazine 5,5‐dioxide was prepared by two different ways from 3,4,5‐triamirio‐1,2,6‐lhiadiazine 1, 1‐dioxide and 3,5‐diamino‐4H‐1,2,6‐thia‐diazine 1, 1‐dioxide respectively. 7‐A:nino‐2‐phenyl‐4H‐vic‐triazolo[4,5‐c] [1,2,6]thiadiazine 5,5‐dioxide was obtained by lead telraacetate oxidation of 3,5‐diamino‐4‐phenylazo‐1, 2, 6‐thiadiazine 1, 1‐dioxide.
New derivatives of 3‐methylisoxazolo[5,4‐b]pyridine
Authors: Camparini Alfredo , Ponticelli Fabio , Tedeschi Piero
Published: April 2009

The synthesis and properties of 4,6‐dichloro‐ (IV), 4‐chloro‐ (XII) and 6‐chloro‐3‐methyl‐isoxazolo[5,4‐b]pyridine (XI) are described. Depending on the reaction conditions compound IV with hydrazine or methoxide gave mono‐ or bi‐substituted products. The halogen atom at the 4‐position was shown to be the more mobile.
Chemical, physicochemical and crystallographical studies in the 1,2,4‐triazole series
Authors: Hénichart J. P. , Houssin R. , Lablanche B. , Baert F. , Devos L.
Published: April 2009

The structure of the condensation product of 1,2,4‐lriuzole and morpholinochloroethane was determined by comparison of its chemical, physicoehemieal and erystallographical characteristics with those of two isomeric compounds prepared by an univocal synthesis.
Synthesis of some N,1‐ and N′,1‐diaryl‐1H‐1,2,4‐triazole‐3,5‐diamines
Authors: Wu M. T.
Published: April 2009

Two novel methods for the preparation of N, 1‐ and N′,1‐diaryl‐1H‐1,2,4‐lriazole‐3,5‐(Hamines are described.
Reactions of epoxy‐1,1,2‐trichloroethane with nudeophiles
Authors: Kline Stanley A. , Van Duuren Benjamin L.
Published: April 2009

Epoxy‐1,1,2‐triehloroethane (1) was synthesized by the autuoxidation of trichloroethylene and was characterized. It was shown to react readily with 2‐mercaptobenzirnidazole (2), 1 ‐melhyl‐2‐mercaptoimidazole (3), p‐nitrolhiophenol (4), and 3,4‐dichlorolhiophenol (5) forming 2‐chloro‐2‐(benzirnidazole‐2‐thio)acelie acid (6), 2‐ehloro‐2‐(1‐methylirnidazole‐2‐thio)aeetic acid (characterized as methyl ester (8)), 2‐chloro‐2‐(4‐nitrolhiothiophenoxy)‐4‐nilrophenylthioaeetate (9), and 2‐chloro‐2‐(3,4‐dichlorothiophenoxy)‐3,4‐dichlorophenylthioaeetale (10), respectively. Base hydrolysis of 9 yielded 2,2‐di(4‐nilrothiophenoxy)acetie acid (11). Adducl 9 decomposed on silica gel yielding p‐nitrophcnyldisulfide (12).
The role of solvent in conjugate additions leading to cis and trans‐1‐Alkyl‐2‐aryl‐3‐carbo(aroyl)aziridines
Authors: Tarburton Phillip , Woller Paul B. , Badger Robert C. , Doomes Earl , Cromwell Norman H.
Published: April 2009

In the formation of cis‐ and trarn‐1‐alkyl‐2‐aryl‐3‐carbo(aroyl)aziridines a change in solvent from benzene to rnethanol in the α‐bromochalone‐primary amine reaction produced an increase in cic isotner. However, the same solvent change resulted in a decrease in the cis/trans ratio when these same aziridines were prepared by the ehalcone‐halogen‐primary amine reaction. These results are rationalized in terms of both an open and chelated enol intermediate thought to be crucial in the relative product formations. Other mechanistic considerations in the product formations are presented.
On the behavior of α‐brominated dimethyl o‐benzenediacetate toward nitrogen nucleophiles. Part II. Reaction of dimethyl α‐bromo‐o‐benzenediacetate with hydrazines
Authors: Cignarella G. , Cerri R. , Savelli F. , Maselli A.
Published: April 2009

Dimethyl α‐bromo‐o‐benzenediacetate (1) condensed with hydrazine and acetylhydrazine to give respectively 1‐carbomethoxy‐2‐amino‐1,4‐dihydro‐3‐(2H)isoquinolinone (2) and its N‐acetyl derivative (9). Replacement of the bromine atom of 1 with the N‐1‐methylhydrazino (3) and the N‐1‐phenylhydrazino (5) groups occurred by allowing 1 to react respectively with methylhydrazine and phenylhydrazine. In the latter case alkylation by 1 at the N‐2 also occurred which led to the formation of the 2‐phenylaminoisoquinolinone (8). Derivatives 3 and 5 smoothly cyclized to the 1‐earbomethoxy‐5(H)‐1,2,3,4‐tetrahydro‐2,3‐benzodiazepin‐4‐ones 4 and 6. A series of derivatives of 2 were also pharmacologically tested as antiinflammatory and CNS depressant agents.
Synthesis in the diazasteroid group VI. A synthesis of 2,3‐dimethoxy‐15‐methyl‐8,15‐diazaestra‐1,3,5(10)triene
Authors: Yamazaki Takao , Nagata Masanori , Matoba Katsuhide , Takahata Hiroki , Castle Raymond N.
Published: April 2009

Homoveratrylamine (II) was condensed with 3‐(2‐carbomethoxyethyl)‐1,3‐dimethyl‐2‐pyrrol‐idone (Ib) to furnish the corresponding amide (III), which was subjected to the Bischler‐Napieralski reaction to afford the corresponding dihydroisoquinoline derivative (IV). Compound V was obtained by the reductive ring closure of Vila which was obtained by the hydrogena‐tion of IV. The stereochemistry of V is proposed to have the anti‐trans‐trans quinolizidine conformation.
Studies on the synthesis of chemotherapeutics. I. Synthesis of 1‐(2‐tetrahydrofuryl)‐5‐fluorouracil [ftorafur] (studies on the syntheses of heterocyclic compounds. Part 703)
Authors: Kametani Tetsuji , Kigasawa Kazuo , Hiiragi Mineharu , Wakisaka Kikuo , Kusama Osamu , Kawasaki Kumeo , Sugi Hideo
Published: April 2009

Synthesis of 1‐(2‐tetrahydrol'uryl)‐5‐fluorouracil [Ftorafur] (1) which is well known as an antitumor agent from 5‐fluorouracil (2) with 2‐alkoxytetrahydrofurans (4) is described. Among these reactions, the best yield was obtained by using 2‐t‐butoxytetrahydrofuran (4h).
Synthetic studies on chemotherapeutics. II. Synthesis of phenyl‐substituted 1,4‐dihydro‐4‐oxonicotinic acid derivatives. [Studies on the syntheses of heterocyclic compounds. Part 704]
Authors: Kametani Tetsuji , Kigasawa Kazuo , Hiiragi Mineharu , Wakisaka Kikuo , Kusama Osamu , Sugi Hideo , Kawasaki Kumeo
Published: April 2009

The thermal cyclization of the arninomethylenemalonates (8) gave the 4‐hydroxynicotinates (9), ethylation of which yieldedN‐ethylated (11) and O‐ethylated products (12). Hydrolysis of 9, 11, and 12 led to the desired nicotinic acids (10, 4, and 13), respectively.
Pyrazolopyrimidine nucleosides. Part VIII The synthesis of certain 4‐substituted pyrazolo[3,4‐d]pyrimidine nucleosides
Authors: Montero Jean Louis G. , Bhat Ganapati A. , Panzica Raymond P. , Townsend Leroy B.
Published: April 2009

1‐(β‐D‐Ribofuranosyl)pyrazolo[3,4‐b]pyrimidine‐4‐thione (6), obtained by a three‐step synthesis from allopurinol riboside (3), was treated with certain alkyl and aryl halides to provide the corresponding 4‐alkylthio derivatives. The nucleoside 4‐methylthio‐1‐(β‐D‐ribofuranosyl)pyra‐zolo[3,4‐d]pyritnidine (7) has served as the precursor for the preparation of the 4‐methylamino (11), 4‐dimethylamino (12), 4‐hydrazino (13), and the 4‐hydroxylamino (14) analogs.
Synthesis of polycyclic fused benzimidazole derivatives
Authors: Giannola Liberohalo , Bajardi Maria Luisa , Palazzo Salvatore
Published: April 2009

Am easy method for the synthesis of tetraeyclie systems containing an imidazole and an iso‐thiazole or an imidazole and a thiazine ring, by reacting 2H‐1,3‐benzothiazine‐2‐thion‐4(3H)one with aromatic primary diarnines is reported. The structures were assigned based upon mass spectra and modes of cleavage of the compounds. The most important fragments are described.
Oxindoles from α‐acyloxyamides
Authors: Barker Marvin W. , Sung Hsiu‐Sun
Published: April 2009

Oxindoies have been obtained in good yields from the reaction of several a‐acyloxy‐α,α‐diphenylacetanilides and boron trifluoride etherate. The reaction probably occurs by hydrolysis of the ester followed by electrophilic substitution of the resultant carbonium ion on the anilide ring.