Výsledky vyhledávání - "H. C. Van Der Plas"

Ring transformations in reactions of heterocyclic halogeno compounds with nucleophiles. Part X: A tracer study of the conversion of 4-chloro-2-phenylpyrimidine into 4-amino-2-phenylpyrimidine

Autor: H. C. Van Der Plas, H. W. van Meeteren

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 86:567-571

It is shown that in radioactive 4-amino-2-phenylpyrimidine, obtained as a minor product in the reaction of 4-chloro-2-phenylpyrimidine-4-14C with potassium amide in liquid ammonia, the 14C label is present in position 4 of the ring. This result prove

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::48d5b96a4f810fabcb1ed9636b6c0cdb
https://doi.org/10.1002/recl.19670860512

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NMR studies on σ-adducts of heterocyclic systems with nucleophiles (Part VII). 1H-NMR investigations on σ-adduct formation of pyridazine, of pyridazine 1-oxide and some of its derivatives with ammonia. A new substitution mechanism

Autor: D. E. Klinge, H. C. Van Der Plas

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 94:233-236

In the reaction of 6-chloro-3-methoxy-4-nitropyridazine 1-oxide with methanolic ammonia and with liquid ammonia, amino-demethoxylation occurs. By using 1H-NMR spectroscopy we observed that with ammonia a σ-adduct at C(5) is formed. The unusual subst

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::1b6c55806803225254ecb760b8a92655
https://doi.org/10.1002/recl.19750941103

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Ring transformation in reactions of heterocyclic halogeno compounds with nucleophiles (XIII): Conversion of some 5-substituted 4-chloro-2-phenylpyrimidines into 4(5)-substituted 2-phenylimidazoles

Autor: H. W. van Meeteren, H. C. Van Der Plas

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 87:1089-1098

5-Amino-4-chloro-2-phenylpyrimidine and 4-chloro-5-methyl-2-phenylpyrimidine are converted into 4(5)-cyano-2-phenylimidazole and 4(5)-ethynyl-2-phenyl-imidazole, respectively, by reaction with potassium amide in liquid ammonia at - 33°.

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::792be68d018f1284e183befe67babdd7
https://doi.org/10.1002/recl.19680870918

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Ring transformations in reactions of heterocyclic halogeno compounds with nucleophiles (XXXVI). Conversion of 4-amino-3-halogenopyridazines into pyrazoles and of 4-amino-3,6-dihalogenopyridazines into 1,2,4-triazoles

Autor: Arie Koudijs, G. Geurtsen, H. C. Van Der Plas, D. E. Klinge

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 93:236-239

On treatment of 4-amino-3-X-pyridazine (X=Cl, Br) with potassium amide in liquid ammonia 4-cyanopyrazole is formed. Under the same reaction conditions 4-amino-3,6-di-X-pyridazine (X=Cl, Br) undergoes a ring contraction into 3-(cyanomethyl)-1,2,4-tria

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::f2c93a94846eb1712dbaedbd20dde816
https://doi.org/10.1002/recl.19740930811

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Reactions of carbon nucleophiles with 4-phenyl- and 4-tert-butyl-5-halogenopyrimidines. On the occurrence of an SRN1 mechanism

Autor: H. C. Van Der Plas, E. A. Oostveen

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 98:441-444

Reaction of 5-X-4-phenylpyrimidine (X = Br, Cl) with the enolate anions of acetone and acetophenone in liquid ammonia yields 5-acetonyl- and 5-phenacyl-4-phenylpyrimidine, respectively. It is shown that these reactions proceed via an SRN1 mechanism.

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::0e86a821fd5680a81b1c9e1315d29901
https://doi.org/10.1002/recl.19790980705

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Ring transformations in reactions of heterocyclic halogeno compounds with nucleophiles (XXX) Reaction of chlorophenyl- and chlorodiphenyl-pyrazines with potassium amide in liquid ammonia

Autor: H. C. Van Der Plas, P. J. Lont

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 92:449-459

While treatment of 2-chloro-3-phenylpyrazine with potassium amide in liquid ammonia yields only 2-amino-3-phenylpyrazine, from 2-chloro-6-phenylpyrazine on the contrary two ring contraction products, 4(5)-phenylimidazole and 2-cyano-4(5)-phenylimidaz

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::68a41b02a82b7cd1d0620195ec7904bf
https://doi.org/10.1002/recl.19730920412

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Ring transformations in reactions of heterocyclic halogeno compounds with nucleophiles (XXVIII) A study of the mechanism of transformation of chloropyrazine into 2-cyanoimidazole using 14C- and 15N-labelling

Autor: H. C. Van Der Plas, P. J. Lont

Publikováno v: Recueil des Travaux Chimiques des Pays-Bas. 92:311-316

The mechanism of the conversion of chloropyrazine into 2-cyanoimidazole by the action of potassium amide in liquid ammonia has been investigated. Using 2-chloro[4′ 15N]pyrazine and 2-chloro[2′ 14C]pyrazine it has been shown that ring contraction

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::41e12588a4b27c6d9303307fbfda1d2e
https://doi.org/10.1002/recl.19730920311

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Synthesis of 5-deazaflavin adenine dinucleotide (5-dFAD) using a modified triester approach

Autor: J. A. J. Den Hartog, J. H. Van Boom, G. A. Stork, G. A. Van Der Marel, H. C. Van Der Plas, P. Smit

Publikováno v: Recueil des travaux chimiques des Pays-Bas = Journal of the Royal Netherlands Chemical Society, 105, 538-544
Recueil des travaux chimiques des Pays-Bas = Journal of the Royal Netherlands Chemical Society 105 (1986)

Starting from D-ribose and 3,4-xylidine, a fifteen-step synthesis is described for the preparation of 5-dFAD (18). The synthesis involves as key intermediates, 5-deazariboflavin (8), its 2′,3′,4′-tris-O-(tetrahydropyranyl) derivative (12) and 2

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef1ba53fd91004b74ecd9a2ac72f8a26
https://doi.org/10.1002/recl.19861051204

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