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91.
V. Naveen Kumar P. Someshwar P. Narsimha Reddy Y. Thirupathi Reddy B. Rajitha 《Journal of heterocyclic chemistry》2005,42(5):1017-1019
The condensation reaction of aldehydes, β‐ketoesters and urea/thiourea in presence of a catalytic amount of CuPy2Cl2 complex proceeded under very mild reaction conditions in high yield (80‐90%). 相似文献
92.
1,4-Disubstituted 1,2,3-triazoles are obtained in excellent yields via a three-component coupling of secondary alcohols, alkynes and trimethylsilyl azide (TMSN3). This one-pot reaction occurs through in situ generation of an azide from the alcohol and TMSN3, followed by 1,3-dipolar cycloaddition of the terminal alkyne to afford the corresponding disubstituted triazoles. 相似文献
93.
Polyethylene glycol (PEG) is found to be an inexpensive, nontoxic, environmentally friendly reaction medium for the conjugate addition of thiols to conjugated alkenes to afford the corresponding adducts in excellent yields under mild and neutral conditions. Products of undesirable side reactions resulting from polymerization are not observed. The use of PEG avoids the use of either acid or base catalysts for this conversion and moreover PEG can be recovered and reused. 相似文献
94.
Benzathine is prepared in good yields from cyanobenzene by a combination of electrochemical hydrogenation and Kolbe electrolysis using nickel and platinum electrodes in the presence of methanolic sodium methoxide in an undivided cell. 相似文献
95.
Venkatapuram Padmavathi Pinnu Thriveni Boggu Jagan Mohan Reddy Adivireddy Padmaja 《Journal of heterocyclic chemistry》2005,42(1):113-116
A new class of five membered heterocycles, thiadiazoles, triazoles and oxadiazoles were prepared from sulfonyl acetic acids via acid hydrazides. 相似文献
96.
N. Rami Reddy G. Sreedevi K. Prabhavathi I. E. Chakravarthy 《Journal of Analytical Chemistry》2005,60(3):252-253
A new spectrophotometric method was developed for the estimation of dopamine. The method is based on the bromination of the dopamine with a solution of excess brominating mixture. After bromination, the excess brominating mixture is treated with potassium iodide to produce a yellow solution. The absorbance of yellow solution was measured at 350 nm on a Spectronic 1001 spectrophotometer against distilled water as a blank.From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 3, 2005, pp. 2842285.Original English Text Copyright © 2005 by Rami Reddy, Sreedevi, Prabhavathi, Chakravarthy.This article was submitted by the authors in English. 相似文献
97.
A dimethylsiloxane diluted polysiloxane side chain co-polymer with non-chiral banana-shaped mesogenic units shows an optically isotropic ferroelectric switching polar smectic C phase (SmCPF) consisting of a conglomerate of homogeneously chiral domains with opposite handedness. 相似文献
98.
J.S. Yadav B.V.Subba Reddy B. Padmavani Ch. Venugopal A.Bhaskar Rao 《Tetrahedron letters》2007,48(26):4631-4633
Enzymatic kinetic resolution of (±)-hydroxytetrahydropyrans has been achieved for the first time by means of lipase-mediated transesterification to afford optically active (2S,4R)-tetrahydropyranyl acetates and (2R,4S)-tetrahydropyranols in excellent yields with high enantioselectivity. Absolute configurations of the tetrahydropyranyl acetates were assigned as (S) by chemical correlation. 相似文献
99.
A highly regioselective ring opening of epoxides and aziridines can be carried out efficiently with acetic anhydride to form the acetates of the corresponding 1,2-diols and 2-amino-alcohols, respectively, using ammonium-12-molybdophosphate (AMP) as a heterogeneous catalyst, at room temperature, in the absence of solvent. 相似文献
100.
Summary
Sensitive and Selective Spectrophotometric Method for the Determination of Trace Amounts of Osmium with 1,2,3-Indanetrione Monothiosemicarbazone
A simple, sensitive and selective spectrophotometric method has been developed for the determination of osmium using 1,2,3-indane-trione monothiosemicarbazone (ITMT). The method is based on the colour reaction between ITMT and osmium(VIII) in hydrochloric acid (0.32–0.60 M) medium. The calibration graph for measurement at 440 nm is linear in the range 1.4–33.6g of osmium per 25ml, with a molar absorptivity of 6.43×104l·mole–1·cm–1. The effect of interferences has been studied and the method applied to the determination of osmium in synthetic samples whose composition correspond to osmiridium or syserkite, with good results. 相似文献