Syntheses of 1,3-Imidazolin-2-Ones and 1,3-Imidazolin-2-Thiones from New Building Blocks, γ-Aminoacetoacetanilides

Straightforward synthesis of biologically valuable nonsymmetrical malonamides under mild conditions

“…19 To our delight, the carbanion rather than the amino group in the primary β-ketoamide 2t attacked the central carbon atom of 1a with high selectivity, and generated the desired product 3r in 68% yield, instead of 3-oxo- N -( p -tolylcarbamoyl)butanamide 4 . 20 To our delight, the structurally novel nonsymmetrical malonamide 3s was synthesized in 92% yield on a 0.5 mmol scale within 2 h under the standard conditions, without heating to facilitate the dissolution of the substrate N , N ′-(1,4-phenylene)bis(3-oxobutanamide) ( 2u ). 4…”

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

“…In the first stage, aminoketones 18 were condensed with isocyanates 10. p-Toluenesulfonic acid (p-TsOH) was added in the second stage to catalyze the cyclization of ureidoketones 8 to the target products 1 (Scheme 27). 56 The combined yields over both stages were 28-84%.…”

Base Controlled Three-Component Regioselective Synthesis of 2-Imino Thiazolines and 2-Thioxoimidazolin-4-ones

“…In path b, a base-promoted intramolecular attack of the N 1 H group at the methyl ester moiety generates thiohydantoin 7 with the liberation of methanol. Thiohydntoin intermediate 7 tautomerizes into 7A, and intermolecular attack of the sulfur atom at the carbon of bromomethyl group subsequently eliminates HBr to yield 2-thioxoimidazolin-4-one 8 17.…”