- Eco-efficient one-pot tandem synthesis of 1-aryl-1H-tetrazol-5-amine by CAN via in situ generated 1-phenylthiourea and heterocumulene
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A simple, cost-effective, environmentally benign, and efficient one-pot tandem approach to the synthesis of pharmaceutically important 1-aryl-1H-tetrazole-5-amines 3a-k and 4a-k has been described. The reaction utilized 1-phenyl thiourea, which was generated in situ from aqueous ammonia and isocyanates 1a-k, for the formation of heterocumenes using sodium azide, triethylamine, and ceric ammonium nitrate (CAN) to obtain various aryl-substituted 1H-tetrazole-5-amines (3a-k) in good to excellent yields.
- Kondhare, Dasharath D.,Bhadke, Venkat V.,Deshmukh, Sushma S.,Wakhradkar, Mahesh G.,Totawar, Balaji B.
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- On the Physicochemical Characterization of 5-Amino-1-aryl-1H-tetrazoles: Electronic Molecule Parameters from the Thermal Isomerization into 5-Arylamino-1H-tetrazoles
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The known thermal isomerization of 5-amino-1-aryl-1H-tetrazoles (A) into corresponding 5-arylamino-1H-tetrazoles (HB) was used to derive physicochemical parameters characterizing the electronic substituent effect on isomerism and dissociation equilibria. For a series of 26 tetrazoles A as starting materials the equilibrium constants (pKi) of isomerization in boiling ethylene glycol at 197°C and the dissociation constants (pKa) of the NH-acidic tetrazoles HB were determined by potentiometric titration of rapidly cooled equilibrium mixtures in water and ethanol/water with KOH at 25°C. The pK values are closely correlated with Hammett's electronic substituent constants σ and can be used as electronic molecule parameters in QSAR or QSPR (QSAR = quantitative structure-activity relationship; QSPR = quantitative structure-property relationship) studies.
- Schelenz, Thomas,Schaefer, Wieland
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p. 197 - 200
(2007/10/03)
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- Benzodiazepine derivatives
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Compounds of Formula (I), and salts and prodrugs thereof, wherein said formula, R 1 represents certain optionally substituted alkyl or C 3-7 cycloalkyl; R 2 represents (II) or (III), where m is 0, 1, 2 or 3; R 9 is H or C 1-6 alkyl; R 10 is imidazolyl, triazolyl or tetrazolyl, and R 11 is H, C 1-6 alkyl or halo; R 3 is C 1-6 alkyl, halo or NR 6 R 7 ; R 4 is C 1-7 alkyl, C 3-10 cycloalkyl, C 3-10 cycloalkylC 1-4 alkyl, C 6-10 bicycloalkyl, optionally substituted aryl, or NR 12 R 13 ; R 5 is H or C 1-4 alkyl; n is 0, 1, 2 or 3; which are CCK and/or gastrin antagonists useful in therapy.
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- Controlled modification of acidity in cholecystokinin B receptor antagonists: N-(1,4-benzodiazepin-3-yl)-N′-[3-(tetrazol-5-ylamino)phenyl]ureas
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The design, synthesis, and biological activity of a novel series of CCK-B receptor antagonists (1) which incorporate a tetrazol-5-ylamino functionality attached to the phenyl ring of the arylurea moiety of L-365,260 are described. In these compounds, the
- Castro, José L.,Ball, Richard G.,Broughton, Howard B.,Russell, Michael G. N.,Rathbone, Denise,Watt, Alan P.,Baker, Raymond,Chapman, Kerry L.,Fletcher, Alan E.,Patel, Smita,Smith, Alison J.,Marshall, George R.,Ryecroft, Wayne,Matassa, Victor G.
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p. 842 - 849
(2007/10/03)
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