Methods for the synthesis of 1-substituted 1H-imidazol-2(3H)-ones

Abstract

Generally applicable methods for the synthesis of 1-substituted 1H-imidazol-2(3H)-ones reported from 1923 to 2014 have been reviewed and presented to the attention of chemists in various fields.

Imidazole Chemistry in Crop Protection

“…Imazethapyr (4), imazamox (5) and imazaquin (6) are mainly used under pre-and postemergent conditions for the control of annual and perennial grasses and broadleaf weeds in soybeans and other crops (Figure 1). [17][18][19][20] There are various routes available for the synthesis of the imidazolinone herbicides, as demonstrated in Scheme 1 for imazethapyr (4). It can be efficiently prepared in only two steps by condensation of diethyl chlorooxalacetate (7) and an enal, in the presence of a buffered ammonia source, to the pyridine diester 8 and its regioselective transformation into imazethapyr (4) with potassium tert-butoxide and -methylvalinamide.…”

“…18,19,21,22 Scheme 1. Synthesis of imazethapyr (4) During the course of the optimization work on imidazolinone herbicides, also several compounds have been prepared, in which the imidazolinone pharmacophore is linked to a bicyclic scaffold, such as the dihydropyranopyridyl derivative 11 23 and the N-methoxypyrrolopyridine derivative 12, 24 which show both excellent postemergence weed control with good soybean selectivity. The thionoimidazoline derivative 13, which is the thiono-analog of one of the two imazamethabenz-methyl regioisomers, displays good control of Sinapis arvensis (wild mustard) and Avena fatua (wild oats) under pre-emergent conditions.…”

“…They are chemically related to the other azoles, such as pyrazole, oxazole and thiazole, but can be also seen as five-ring equivalent of the diazine pyrimidine, in which two ring nitrogens are separated by one ring carbon atom as well. The progress in preparative investigation on imidazoles, 1 benzimidazoles, 2 imidazolines 3 and imidazolones 4 has been summarized in review articles. Also, the antibacterial, 5 anticancer, 6 antifungal, 7 anti-inflammatory, 8 antitubercular 9 and antiviral 10 activity of imidazole derivatives has been reviewed recently.…”

Unusual formation of imidazooxazolone in the reaction of 1-[(2-acetylamino)ethyl]imidazolone with KSCN in the presence of AcOH

“…This approach was chosen considering published data on the synthesis of 1-substituted imidazolinones. [29][30][31][32][33][34] N-Oxides 8a,b were synthesized by condensation of accessible reactants: N-acetylalkylenediamines 9a,b (prepared by acylation of ethylenediamine [35][36][37] or prophylendiamine 38 ), paraformaldehyde, and α-ketooxime 10 (Scheme 4).…”

Recent Advances in the Catalytic Synthesis of Imidazolidin-2-ones and Benzimidazolidin-2-ones

“…However, particularly important contributions beyond the timespan will be also considered. The preparation of hydantoins [14] and 2-imidazolones [15] will not be treated in view of very recent reviews on these topics. For the convenience of the reader, essential breaking and forming bonds are highlighted in blue and red, respectively.…”