Assignment of Amide Structures to the Supposed 2,3-Dihydro-2-benzimidazolols and their Acylation Products

Abstract

On the basis of its infrared absorption spectrum the reaction product of a-benzamidoisobutyric acid with phosphorus tribromide has been assigned the structure, 2-phenyl-4,4-dimethyl-5(4)-oxazolone hydrobromide rather than a-benzamidoisobutyryl bromide. This is the first reported instance of an infrared absorption spectrum of a compound of this type.

Chemical transformations of 7,9-disubstituted purines and related heterocycles. Selective reduction of imines and immonium salts

“…Under the same conditions 7,8-dihydro-7,9-dimethylguanine (2b) gave 91 and 94% reduction, respectively. As shown in Table VI, the extent of reduction of 21 effected by individual compounds was generally consistent with the rate at which those Benzylidenebenzyl-Cyclohexylidenepyrroli-Benzylideneaniline (20) amine (21) dinium perchlorate (22) 8 h, 8 h, (48)c…”

“…19 No evidence was presented in support of the position assigned to the formyl group, however, in spite of earlier evidence for the formation of two products from the ring opening of 1,2,3,5-tetramethylbenzimidazole. 20 Similarly, Haines et 11 and observed the formation of a pyrimidine which was homogeneous as judged by paper chromatography. This species was assigned the IVs-formyl structure 14 by virtue of the fact that a compound identical with its aglycone (15) could be obtained by formylation of 16.21 By analogy with the earlier work, the 5-formyl isomers have also been reported as the exclusive products resulting from the ring opening of 7-methylxanthosine22 and 6-thio-7-methylguanosine.…”

Facile synthesis of colorimetric histone deacetylase substrates

“…Dynamic Article Links www.rsc.org/chemcomm COMMUNICATION formation might even be reversible, which raises concerns about racemization of the Lys(Ac) moiety. 19,20 In contrast to urethanebased protection groups, N-arenesulfonyl protectants cannot form oxazolones from amino acid halides. 21 Furthermore, the greater inductive effect of the sulfonyl moiety increases the reactivity of the respective acid chlorides.…”

Stable heteroaromatic carbenes of the benzimidazole and 1,2,4-triazole series

“…the products of the azolium ring opening of the intermediate 2-hydroxy-2Н-azolines were confirmed 58,59 . However, in aqueous media, the ionic azolium hydroxides can be stabilized and characterized, and have been shown to be stable at room temperature for at least for one week 60 . It is also known that, when stabilized by electron withdrawing substituents (СООМе), 2-hydroxybenzimidazolines can exist in a covalent form 61 .…”