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  • Fused Pyrazoles  (1)
  • Sperm motility  (1)
  • Springer  (2)
  • 2020-2022
  • 2015-2019
  • 1980-1984  (2)
  • 1
    ISSN: 1434-4475
    Keywords: Enaminonitriles ; Fused Pyrazoles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Reaktion von 5-Amino-4-cyano-3-phenylpyrazol (1) mit Acrylnitril oder Ethylacrylate ergibt 4-Cyano-3-phenyl-4,5,6,7-tetrahydro-5-oxopyrazolo-[1,5-a]-pyrimidin (2). Die Reaktion von1 mit Harnstoff, Thioharnstoff und7. Ethyl acetoacetat ergibt die Pyrazolopyrimidinderivate6a,6b und7. Andererseits entsteht das Thioharnstoffderivat4 durch die Reaktion von1 mit Benzoylisothiocyanat. Diazotiertes1 koppelt mit Malononitril und Ethylcyanoacetat zu den Pyrazolopyrimidinen10 und11, die Kopplung mit α-chloroacetoacetic ester und Acetylaceton ergibt jedoch die Hydrazone12 und13.
    Notes: Abstract 5-Amino-4-cyano-3-phenylpyrazole (1) reacts with acrylonitrile or ethyl acrylate to yield 4-cyano-3-phenyl-4,5,6,7-tetrahydro-5-oxopyrazolo-[1,5-a]-pyrimidine (2). With urea, thiourea and ethyl acetoacetate1 gives the pyrazolopyrimidine derivatives6a,6b, and7 respectively. On the other hand, compound1 reacted with benzoylisothiocyanate to give the corresponding thiourea derivative4. Diazotized1 was coupled with malononitrile and ethyl cyanoacetate to yield the pyrazolopyrimidine derivatives10 and11, respectively, whereas on coupling with α-chloro acetoacetic ester and with acetylacetone the hydrazones12 and13 were obtained.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 208 (1980), S. 35-45 
    ISSN: 1432-0878
    Keywords: Tick spermatozoa ; Membrane specialization ; Sperm motility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The spermatozoon of Amblyomma hebraeum is about 200 μm long and comprises: (1) a thick, club-shaped anterior part, about 20 μm long bearing at its apex a “tactile” hemisphere, and (2) an elongated tail-like part, about 180 μm long. The surface of the “tactile” hemisphere is covered by numerous bulbous expansions, attached to it by short stalks. The base of the hemisphere is surrounded by a fringe of thin motile processes; the remaining surface of the spermatozoon is covered with long cellular processes which run more or less parallel to one another. The membrane-associated particles found on the membrane beneath the cellular processes are regularly arranged as groups of parallel strands. The external surface of the so-called “peripheral granules”, as revealed by freeze-etching, is smooth with a very small number of particles. Internally the particles exhibit a regular hexagonal pattern which has not been observed, so far, on any other membrane of these sperm cells. The regional specialization of the spermatozoon surface membrane in relation to sperm motility is discussed. The results obtained indicate that processes of three types: (1) bulbous expansions, (2) motile processes, and (3) cellular processes are regional specializations, all engaged in aspects of sperm motility.
    Type of Medium: Electronic Resource
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