- 5a,10b-dihydrobenzofuro[2,3-b]benzofuran type compounds and related products from p-substituted phenols and glyoxal
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(Chemical Equation Presented) Condensation reactions of glyoxal with p-substituted phenol derivatives 1a-f have been carried out and the corresponding 5a,10b-dihydrobenzofuro[2,3-b]benzofuran 4a-f type compounds were obtained in good to excellent yields.
- Rahmatpour, Ali
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- A novel and efficient synthesis of 3-aryl and 3-heteroaryl substituted-1H-indazoles and their Mannich derivatives
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A general and highly convenient procedure for the synthesis of 3-heteroaryl and 3-aryl substituted-1H-indazoles has been developed. These compounds (3a-f) were synthesized in good yield by refluxing the NaHSO3 adduct of heteroaromatic and aromatic aldehyde and phenyl hydrazine in DMF. This procedure is more general and shorter than earlier methods. Five new 3-hetero-aryl substituted-1H-indazoles were synthesized and characterized. New Mannich derivatives of 3-(1H-pyrrol-2-yl)-1H-indazole (3a) and 3-(1H-indol-3-yl)-1H-indazole (3b) were prepared from morpholine and formaldehyde.
- Servi, Sueleyman,Akguen, Z. Ruestem
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p. 3399 - 3405
(2007/10/03)
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- Kinetics, Mechanism, and Thermodynamics of Glyoxal-S(IV) Adduct Formation
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The reversible addition of glyoxal (ethanedial) and S(IV) to form glyoxal monobisulfite (GMBS) was studied spectrophotometrically over the pH range of 0.7-3.3.Far from equilibrium, the rate of GMBS formation is given by d/dt = (k1,appα1) + k2,appα2), where = + + , = + -> + 2->, α1 = ->/, and α2 = 2->/.The apparent rate constants, k1,app = 0.13 M-1 s-1 and k2,app = 2.08E3 M-1 s-1, are pH independent functions of the dehydration equilibrium constants of (CH(OH)2)2 and CHOCH(OH)2, and intrinsic rate constants for the reaction of HSO3- and SO32- with unhydrated and singly hydrated glyoxal.Glyoxal dibisulfite (GDBS) and GMBS were shown to dissociate with a rate given by d/dt = -1 + k"-1KD3 + (k'-2K'a2 + k"-2K"a2KD3)/+>>t + -3 + k-4Ka3/+>>t, where k-1 and k-2 correspond to the release of bisulfite and sulfite, respectively, from unhydrated and hydrated GMBS species; k-3 and k-4 correspond to the release of bisulfite and sulfite from GDBS; KD3 is the dehydration constant for GMBS; K'a2, K"a2, and Ka3 are acid dissociation constants.Stability constants for the formation of GMBS and GDBS were determined to be cK1 = ->/(-) = 2.81E4 M-1 and cK2 = -)2>/(->->) = 1.45E4 M-1 at 25 deg C and μ = 0.2 M.
- Olson Terese M.,Hoffmann, Michael R.
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p. 533 - 540
(2007/10/02)
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