Structures of Addition Products of Acetylenedicarboxylic Acid Esters with Various Dinucleophiles. An application of C, H-spin-coupling constants
作者:Ulrich Vögeli、Wolfgang von Philipsborn、Kuppuswamy Nagarajan、Mohan D. Nair
DOI:10.1002/hlca.19780610207
日期:1978.3.8
Heterocyclic compounds obtained by addition of acetylenedicarboxylicacidesters to thioureas, cyclic amidines and o-difunctionalized aromatic systems have been studied by 13C-NMR. In particular, C, H-spin-coupling constants over two and three bonds were used to differentiate between the various constitutional isomers and to establish the configuration of trisubstituted exocyclic C, C-double bonds
Efficient Conversion of Substituted Aryl Thioureas to 2-Aminobenzothiazoles Using Benzyltrimethylammonium Tribromide
作者:Alfonzo D. Jordan、Chi Luo、Allen B. Reitz
DOI:10.1021/jo0349431
日期:2003.10.1
The reaction of molecular bromine (Br2) with arylthioureas is known to produce 2-aminobenzothiazoles (Hugerschoff reaction). We show here that benzyltrimethylammonium tribromide (1, PhCH2NMe3Br3), a stable, crystalline organic ammonium tribromide (OATB), can be readily utilized as an alternative electrophilic bromine source. It is easier to control the stoichiometry of addition with an OATB, which
Quantitative Solid-State Reactions of Amines with Carbonyl Compounds and Isothiocyanates
作者:Gerd Kaupp、Jens Schmeyers、Juergen Boy
DOI:10.1016/s0040-4020(00)00511-1
日期:2000.9
solid anhydrides to give diamides (therefrom imides) or amidic carboxylic salts or imides, with solid imides to give diamides, with solid lactones or carbonates to give functionalized carbamic esters, with polycarbonates to give degradative aminolysis, and with solid isothiocyanates to give thioureas. Diamides give imides by solid-state thermolysis or acid catalysis. Various double, two-step, 3-cascade