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  • 1
    Electronic Resource
    Electronic Resource
    Reaktionen von 3-Dimethylamino-2,2-dimethyl-2H-azirin mit. NH-aciden Heterocyclen; Synthese von 4H-imidazolen (1979)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 62 (1979), S. 768-778 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 3-Dimethylamino-2,2-dimethyl-2H-azirine with NH-Acidic Heterocycles; Synthesis of 4H-ImidazolesIn this paper, reactions of 3-dimethylamino-2,2-dimethyl-2H-azirine (1) with heterocyclic compounds containing the structure unit CO—NH—CO—NH are described. 5,5-Diethylbarbituric acid (5) reacts with 1 in refluxing 2-propanol to give the 4H-imidazole derivative 6 (Scheme 2) in 80% yield. The structure of 6 has been established by X-ray crystallography. Under similar conditions 1 and isopropyl uracil-6-carboxylate (7) yield the 4H-imidazole 8 (Scheme 3), the structure of which is deduced from spectral data and the degradation reactions shown in Scheme 3. Hydrolysis of 8 with 3N HCl at room temperature leads to the α-ketoester derivative 9, which in refluxing methanol gives dimethyl oxalate and 5-dimethyl-amino-2,4,4-trimethyl-4H-imidazole (10). On hydrolysis the latter is converted to the known 2,4,4-trimethyl-2-imidazolin-5-one (11) [6]. Quinazolin-2,4 (1H, 3H)-dione (12) and imidazolidinetrione (parabanic acid, 14) undergo with 1 a similar reaction to give the 4H-imidazoles 13 and 15, respectively (Schemes 4 and 5).In Scheme 6 two possible mechanisms for the formation of 4H-imidazoles from 1 and heterocycles of type 16 are formulated. The zwitterionic intermediate f corresponds to b in Scheme 1. Instead of dehydration as in the case of the reaction of 1 with phthalohydrazide [3], or ring expansion as with saccharin and cyclic imides [1] [2], f, undergoes ring opening (way A or B). Decarboxylation then leads to the 4H-imidazoles 17.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19790620314
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  • 2
    Electronic Resource
    Electronic Resource
    Photochemische Synthesen potentiell hypoglykämisch wirkender 3-Oxazoline (1985)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 68 (1985), S. 584-591 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical Syntheses of 3-Oxazolines which Possibly Exhibit Hypoglycemic ActivityReactions of photochemically generated benzonitrile methylides 2 with carbonyl compounds 3 yielded 3-oxazolines of the types 5 and 6 (Scheme 1). Photooxidation of 5-[p-(dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazoline (5a) gave 4′-(2,2-dimethyl-4-phenyl-3-oxazolin-5-yl)-N-methylformanilide (6r) which could be transformed to 2,2-dimethyl-5-[p-(methylamino)phenyl]-4-phenyl-3-oxazoline (6s) by photodecarbonylation. Thirty 3-oxazolines of types 5 and 6 have been synthesized and tested by oral and/or intraperitoneal administration to starved rats and obese-hyperglycemic mice.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19850680308
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  • 3
    Electronic Resource
    Electronic Resource
    Photochemische und chemische Synthesen biologisch aktiver 3-Oxazoline (1985)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 68 (1985), S. 600-605 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical and Chemical Syntheses of Biologically Active 3-OxazolinesUsing the photoreaction of 2H-azirines with carbonyl compounds, the 2,2-dimethyl-3-oxazolines 5a, 5b, and 6a have been obtained which bear a mono- or dichlorophenyl substituent at C(4) of the five-membered heterocycle and pyridyl at C(5). These compounds exhibit interesting activities against phytopathogenic fungi. Because 6a had been selected for field testing, its photochemical preparation was supplemented by a chemical synthesis. However, the overall performance of 6a in the field was inferior to some of the recently introduced agricultural fungicides of the ergosterol biosynthesis inhibitor type. Although 16 additional 3-oxazolines with varied substituents have been prepared, the fungicidal activity found with 6a could not be improved.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19850680310
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  • 4
    Electronic Resource
    Electronic Resource
    Catechol-O-methyltransferase-Inhibiting Pyrocatechol Derivatives: Synthesis and Structure-Activity Studies (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 952-968 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Nitro- and 3-cyanopyrocatechols bearing electron-withdrawing substituents at C(5) have been found to inhibit the enzyme catechol-O-methyltransferase. Structure-activity studies are discussed on the basis of the pharmocological data of 50 compounds (cf, Chapt. 4, Tables 1-7). Some 3-nitro-5-aroylpyrocatechols (Type A2, Table 1) fulfil the requirements for a clinical candidate, being orally active, specific, reversible, and relatively short-acting. The chemical work involved is illustrated by describing a choice of exemplary syntheses, dealing with compounds 9, 11, 14, 18, 22, 24, 25, 35, 41, and 42 (Chapt. 5, Schemes 1-10).
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720511
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  • 5
    Electronic Resource
    Electronic Resource
    Derivatives of (2R)-N-Glyoxylbornane-10,2-sultam and Their Use as auxiliaries in the diastereoselective spirocyclization of 2-substituted tryptamines7th Communication on ‘Indoles, Indolenines, and Indolines’; 6th communication: [1]. (1994)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 77 (1994), S. 615-621 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A crude hydrate 6 and a crystalline hemiacetal 7 of glyoxylamide 4 were prepared from crotonamide 5 (Scheme 2). Particularly hemiacetal 7, but also 6 and the ‘dimer’ 8 (obtained from 7) may serve as homochiral auxiliaries. The structure of 8 was determined by X-ray analysis. By arenesulfonyl halides, tryptimines 12-14 of 4 were diastereoselectively transformed into spirotricycles 15-17 and 19.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19940770304
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesen des Analgetikums 2-[1-(m-Methoxyphenyl)-2-cyclohexen-1-yl]-N,N -dimethyl-äthylaminHerrn Professor Dr. A. Hürlimann zum 60. Geburtstag gewidmet (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 570-585 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of the Analgesic 2-[1-(m-Methoxyphenyl)-2-cyclohexen-1-yl] -N,N-dimethyl-ethylamineThree principal routes to 2-[1-(m-methoxyphenyl)-2-cyclohexen-1-yl]- N,N-dimethyl-ethylamine (13), a compound with interesting analgesic properties, are described. In the first, derivatives of [1-(m-methoxyphenyl)-2-cyclohexen-1-yl]acetic acid (10) (alternatively the ethyl ester 29, the dimethylamide 32 or the nitrile 34) serve as crucial intermediates. All three can be synthesized from 2-(m-methoxyphenyl)cyclohexanone (1) by sequences comprising successively C-alkylation (1→2,4,5; Scheme 1), reduction of the ketone carbonyl group (2→6;4→18;5→19; Scheme 1 and 2) and elimination (16→29; 18→32; 19→34; Scheme 2). The relative configuration of the cyclohexanols 16, 18, 19 and of a series of related compounds is established by chemical correlation with the lactone 30 the structure of which follows from 1H-NMR. data (Scheme 2). The second route creates the intermediates 29 and 32 by ester- or amide-enolate-Claisen-type-rearrangement reactions starting from 3-(m-methoxyphenyl)-2-cyclohexen-1-ol (39; Scheme 3). Compounds 29, 32 and 34 are transformed into the target molecule 13 by standard reactions. A Hofmann elimination of the quaternary ammonium fluoride 50 (X=F), derived from the known cis-perhydroindoline 48, is the essential step in the third approach to 13 (Scheme 4).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660217
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  • 7
    Electronic Resource
    Electronic Resource
    1-[(Dimethylamino)methyl]pyrrol aus Trimethyl (1-pyrrolyl)-ammonium-Ion (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 1860-1864 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-[(Dimethylamino)methyl]pyrrole from Trimethyl (1-pyrrolyl)ammonium IonTrimethyl (1-pyrrolyl)ammonium iodide (5a) and the corresponding p-toluene-sulfonate 5b are transformed by strong bases into 1-[(dimethylamino)methyl]-pyrrole (9), i.e. into a N-Mannich base, a type of compound novel in the pyrrole series. In this reaction, which is very fast in DMSO, the cation of compounds 5 is deprotonated to form the nitrogen ylide 6. The latter undergoes a Stevens-type rearrangement to 9. Several facts, namely the negative outcome of a cross-reaction experiment with 3,4-dimethylpyrrole and of an attempt to obtain 9 from pyrrole and dimethyl (methylidene)ammonium iodide in the presence of one equivalent of sodium methoxide, as well as unsuccessful CIDNP studies point to a rearrangement mechanism via the contact ion pair 12.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660626
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  • 8
    Electronic Resource
    Electronic Resource
    Optically Pure Isoproterenol Analogues With Side Chains Containing an Amide Bond: Synthesis and biological properties (1988)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 71 (1988), S. 320-336 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The isoproterenol analogues 4a and 4b, synthesized as mixtures of Diastereoisomers, were shown to possess very potent β-adrenoceptor agonistic activity. Therefore, the four possible diastereoisomers of 4a have been synthesized and tested for inotropic activity. The (6R, 2′R)-diastereoisomer turned out to be the most interesting one. Consequently, also (6R,2′R)-4b has been prepared and tested. For the diastereoselective synthesis, three variants have been elaborated: (i) coupling of epoxides 12 with amines 27 (Scheme 6); (ii) coupling of the activated glycol 17 with the amine 22 (Scheme 8); (iii) diastereoselective hydrogenation of the amino ketone 31 (Scheme 7). Both (6R,2′R)-4a and (6R,2′R)-4b show long lasting positive inotropic activity after intravenous as well as oral administration and are at least three times as potent as rac-isoproterenol. In the anesthetized dog, a good separation of positive inotropic and positive chronotropic effects is observed. In conscious dogs, however, heart rate and contractile force increase to the same extent (possibly due to reflex tachycardia).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19880710204
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  • 9
    Electronic Resource
    Electronic Resource
    Diastereoselective Spirocyclization of C-(Alkyloxycarbonyl)formimines of 2-Substituted 1HIndole-3-ethanamines (= Tryptamines): Basic Studies. 5th Communication on Indoles, Indolenines, and Indolines4th communication: [1]. (1990)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 73 (1990), S. 439-454 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: C-(Alkoxycarbonyl)formimines of type 15-18 were derived from the 2-substituted tryptamines 2, 9, 10, and 11 and transformed with tosyl chloride into tricyclic 3-spiroindoles of types 19-22 (Scheme 3). The influence of the homochiral alkoxy moieties A-D on the stereochemical outcome of this reaction was studied. Good-to-excellent diastereoselectivities were observed with the (-)-8-(phenylmenth-3-yl)oxy group (B) as homochiral auxiliary. The structures of the tricycles 4, (2′R,3S)-19B, and (2′S,3R)20C were established by X-ray analysis, the structures of the others by NOE and CD studies, and by chemical correlation. Possibilities to explain the steric course of the spirocyclizations are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19900730224
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  • 10
    Electronic Resource
    Electronic Resource
    Diastereoselective Spirocyclization of Imines of 2-Substituted 1H-Indole-3-ethylamines ( = Trypatamines): Variation of the electrophile and the substituent at C(2) and its influence on the steric outcome. 6th Communication on indoles, indolenines, and indolines5th communication: [1]. (1992)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 75 (1992), S. 282-287 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tryptimines of type 7 form with various acyl halogenides EX preferentially tricycles of type 8 (cf: Scheme 2). The homochiral imines 9 and 17 are transformed into (2′R,3S)-configurated products. The synthetic and mechanistic importance of these results is discussed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19920750124
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