نتایج جستجو برای: haack series
تعداد نتایج: 351102 فیلتر نتایج به سال:
Reaction of carbohydrates with Vilsmeier reagent: a tandem selective chloro O-formylation of sugars.
A convenient and efficient method for selective replacement of the primary hydroxyl groups of sugars by chlorine with concomitant O-formylation, compatible with the presence of a variety of functional groups, has been developed using the Vilsmeier-Haack reaction. Sugars having free primary hydroxyl groups mostly afforded the chloro-O-formylated product while sugars devoid of primary hydroxyl gr...
5-Acetoxymethyl- and 5-hydroxymethyl-2-vinylfuran were synthesized by two routes. The first route starts from 2-methylfuran and the second from furfuryl acetate. The latter route, involving successive Vilsmeier-Haack and Wittig reactions, is suitable for producing 5-acetoxymethyl-2-vinylfuran and 5-hydroxymethyl-2 vinylfuran in 68% and 60%yields, respectively.
Vilsmeier-Haack reaction of 2,3,3-trimethyl-3H-benzo[g]indole, then aqueous basic work-up, leads to benzo[g]indol-2-ylidene- malondialdehydes. These react with various arylhydrazines and quinolin-2-ylhydrazine to form 3,3-dimethyl-2-(1-aryl-1H-pyrazol-4-yl)- 3H-benzo[g]indoles in good yields.
Sir, The letter by Haack et al. (2014) provides important information confirming the role of the thiamine transporter hTHTR2 in Leigh syndrome and the beneficial effect of biotin and/or thiamine treatment for patients harbouring mutations in the gene encoding hTHTR2, SLC19A3. In recent years many new pathogenic mutations have been reported in SLC19A3 resulting in several age-related neurologica...
Chalcones were synthesized by reacting indole-3-aldehyde, prepared by Vilsemeir Haack reaction with 4-substituted acetophenone in ethanolic KOH solution. These chalcones were immediately reacted with hydroxylamine hydrochloride in presence of glacial acetic acid as reagent to obtain the corresponding isoxazole derivatives. The synthesized heterocycles were characterized on the basis of physical...
An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. T...
Janet M. Mullington, PhD1; Sabra M. Abbott, MD, PhD2; Judith E. Carroll, PhD3; Christopher J. Davis, MS, PhD4; Derk-Jan Dijk, PhD5; David F. Dinges, PhD6; Philip R. Gehrman, PhD7; Geoffrey S. Ginsburg, MD, PhD8; David Gozal, MD, MBA9; Monika Haack, PhD1; Diane C. Lim, MD10; Madalina Macrea, MD, MPH, PhD11,12; Allan I. Pack, MBChB, PhD, FRCP13; David T. Plante, MD14; Jennifer A. Teske, PhD15; Ph...
Diverse meso-aminophenyl-, hydroxyphenyl-, and phenyl-substituted heptamethine cyanine dyes were prepared by a modified Suzuki--Miyaura method in good yields. In addition, direct Suzuki coupling of Vilsmeier--Haack reagent extends the procedure to the synthesis of otherwise difficult cyanine dyes containing multiple heteroatoms in the indolium ring. The new compounds possess excellent spectral ...
the present study aimed to investigate representation of discourse markers and metadiscourse markers in conversations and readings of general elt coursebook series used in the language centers of iran. to this aim, four elt coursebooks popularly taught in language centers of this country were analyzed based on fung and carter’s (2007) framework regarding discourse markers and hyland’s (2005) fr...
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