Studies on cardiotonic agents. IV. Synthesis of novel 1-(6,7-dimethoxy-4-quinazolinyl)piperidine derivatives carrying substituted hydantoin and 2-thiohydantoin rings.

Novel and Potent 6-Chloro-3-pyridinyl Ligands for the α4β2 Neuronal Nicotinic Acetylcholine Receptor

“…The imidazolidone ( 11 ) and imidazole ( 12 ) derivatives were obtained as above from 2-imidazolidone or imidazole with CCMP. In synthesis of the 2-imidazolinethione analogue 13 , 1-[(2-chloro-5-pyridinyl)methyl]ethylenediamine was refluxed in ethanol with excess carbon disulfide . The acyclic compound 14 was obtained by reacting CCMP with 70% ethylamine in water, followed by treatment with methyl isothiocyanate, and then reaction with methyl iodide in acetone followed by anhydrous ammonia in ethanol as before.…”

“…In synthesis of the 2-imidazolinethione analogue 13, 1-[(2-chloro-5pyridinyl)methyl]ethylenediamine was refluxed in ethanol with excess carbon disulfide. 19 The acyclic compound 14 was obtained by reacting CCMP with 70% ethylamine in water, 20 followed by treatment with methyl isothiocyanate, 21 and then reaction with methyl iodide in acetone followed by anhydrous ammonia in ethanol as before. The deschloro analogue (15) of 1 was produced as above in the guanidine-type analogues from 3-(chloromethyl)pyridine.…”

“…1-[(6-Chloro-3-pyridinyl)methyl]pyrrolidine (19). CCMP (162 mg, 1.0 mmol), pyrrolidine (167 µL, 2.0 mmol), and K2CO3 (138 mg, 1.0 mmol) in acetonitrile (10 mL) were refluxed overnight.…”

The Bucherer–Bergs Multicomponent Synthesis of Hydantoins—Excellence in Simplicity

“…Additionally, the use of a two-phase system such as aqueous KOH/n-BuOH and PEG 600 as a phase transfer catalyst drastically reduced the quantity of side product, increasing the yield of phenytoin (87-93%) [123]. Although the reaction of α-amino esters with amines and phosgene (or carbonyldiimidazole as a modern alternative) [16,[124][125][126][127] or cyclization of urethans [128] as well as cyclization of α-ureido esters [63] are also good alternatives for the synthesis of hydantoins, these methods suffer from low availability of common intermediates-α-amino acid amides, which, in general, are prepared in several steps. However, in some cases, this synthetic approach represents the most suitable method to obtain desirable hydantoin derivatives in a reasonable yield.…”

Synthesis of Hydantoins from Enantiomerically Pure α-Amino Amides without Epimerization

“…Recently, in the course of conducting a structure−activity relationship (SAR) study, attempts to prepare hydantoin ( S )- 5 by cyclizing α-amino amide 4 in the presence of 1,1‘-carbonyldiimidazole (CDI) were made (Scheme ) . Although cyclization did proceed as expected, complete racemization was observed. , Bis(4-nitrophenyl)carbonate and 4-nitrophenyl chloroformate have been reportedly employed in place of CDI for this type of transformation with good stereochemical integrity. However, some difficulty can be realized in the separation of the desired hydantoin products from the byproduct, 4-nitrophenol.…”