Bucherer–Bergs Multicomponent Synthesis of Hydantoins: Comparison
Please note this is a comparison between Version 2 by Enzi Gong and Version 1 by Miroslav Koóš.

The Bucherer–Bergs reaction is one of the most convenient general methods for the preparation of 5-substituted and 5,5-disubstituted hydantoins (imidazolidine-2,4-diones, 2,4-dioxoimidazolidines). Generally, in this multicomponent reaction, the aldehyde or ketone in aqueous ethanol is heated at 60–70° with potassium (or sodium) cyanide and ammonium carbonate to produce directly hydantoins 1.

  • hydantoins
  • aldehyde
  • ketone
  • multicomponent reaction
  • Bucherer–Bergs reaction

1. Overview

Hydantoins and their hybrids with other molecules represent a very important group of heterocycles because they exhibit diverse biological and pharmacological activities in medicinal and agrochemical applications. They also serve as key precursors in the chemical or enzymatic synthesis of significant nonnatural α-amino acids and their conjugates with medical potential. This review provides a comprehensive treatment of the synthesis of hydantoins via the Bucherer–Bergs reaction including the Hoyer modification but limited to free carbonyl compounds or carbonyl compounds protected as acetals (ketals) and cyanohydrins used as starting reaction components. In this respect, the Bucherer–Bergs reaction provides an efficient and simple method in the synthesis of important natural products as well as for the preparation of new organic compounds applicable as potential therapeutics. The scope and limitations, as well as a comparison with some other methods for preparing hydantoins, are also discussed. 

2. Bucherer–Bergs Reaction 

The Bucherer–Bergs reaction is one of the most convenient general methods for the preparation of 5-substituted and 5,5-disubstituted hydantoins (imidazolidine-2,4-diones, 2,4-dioxoimidazolidines). Although the reaction was first discovered by Bergs [1] (but the first formation of 5,5-dimethylhydantoin from a mixture of acetone and hydrocyanic acid exposed to sunlight for a period of 5–7 months was observed by Ciamician and Silber in 1905 [2]), it is usually credited to Bucherer, who elaborated most of the experimental conditions and applications [3,4,5][3][4][5]. Generally, in this multicomponent reaction, the aldehyde or ketone in aqueous ethanol is heated at 60–70° with potassium (or sodium) cyanide and ammonium carbonate to produce directly hydantoins 1 (Scheme 1).
Scheme 1. General reaction scheme of the Bucherer–Bergs reaction. R and R1 varied alkyl or aryl substituent.
This reaction works well for aliphatic and aromatic aldehydes or ketones and for cyclic ketones despite some reports concerning the failure of this reaction. For such difficult cases, the use of acetamide (formamide as well as dimethylformamide) as a solvent has been recommended [6,7][6][7]. It was found that ultrasonication could also accelerate hydantoin formation [8]. Alternatively, better yields of hydantoins offer the Hoyer modification [9]. In this case, the standard reaction mixture is heated in the atmosphere of CO2 in a closed system at elevated pressure. Because of the wide applicability of the Bucherer–Bergs reaction, it has formerly been proposed as an analytical method for identifying ketones [10].
Hydantoins may be regarded as cyclodehydrated hydantoic acids (α-ureido acids), and this is reflected in their properties because both these compounds are readily interconvertible. Several natural or synthetic hydantoins themselves or their conjugates with other molecules exhibit diverse biological and pharmacological activities in medicinal, such as antimicrobial [11[11][12][13][14][15],12,13,14,15], antiviral [16,17,18][16][17][18], antitumor [19,20[19][20][21][22],21,22], antiarrhythmic [23[23][24][25][26],24,25,26], anticonvulsant [27[27][28][29][30][31][32][33][34],28,29,30,31,32,33,34], antihypertensive [35], antidiabetic [36,37,38,39][36][37][38][39], and agrochemical, such as herbicidal and fungicidal [40[40][41][42][43][44][45],41,42,43,44,45], applications. The studies on the biological activities of hydantoins has made great progress during the last three decades, and hydantoin derivatives have been therapeutically applied or are in the stage of investigation (Figure 1). For example, Phenytoin (Phenytek®, Dilantin®, Epanutin®, Diphenin®)—an antiepileptic drug—is still the drug of choice for the treatment of generalized tonic–clonic seizures (grand mal epilepsy) and focal motor seizures [29,46,47,48,49][29][46][47][48][49]; today, Phenytoin has found new applications because of the neuro- and cardioprotective properties [50,51][50][51]; Mephenytoin (Mesantoin®; it is no longer available in the US or the UK) and Fosphenytoin (Cerebyx®, Prodilantin®) are also effective anticonvulsants, the latter is used only in hospitals for the short-term (five days or less) treatment of epilepsy [52]; Nitrofurantoin (Furadantin®, Macrobid®, Macrodantin®) and Nifurtoinol (Urfadyn®)—produces antibacterial activity effective for the treatment of urinary tract infections [53,54,55][53][54][55]; Nilutamide—produces an antiandrogenic effect in the treatment of an advanced stage of the carcinoma of the prostate [19,20,22][19][20][22]; Sorbinil—an aldose reductase inhibitor that blocks the formation of sorbitol from excess glucose and thus may prevent many diabetic neuropathies [56,57,58][56][57][58]; Dantrolene (Dantrium®)—used to treat malignant hyperthermia, neuroleptic malignant syndrome, ecstasy intoxication, and muscle spasticity (stiffness and spasms) caused by conditions such as a spinal cord injury, stroke, cerebral palsy, or multiple sclerosis and is currently the only specific and effective treatment for malignant hyperthermia [59]; Azimilide—an investigational class III anti-arrhythmic drug that blocks fast and slow components of the delayed rectifier cardiac potassium channels (until now, it has not been approved for use in any country but is currently in clinical trials in the United States) [60]. Iprodione (Rovral®, Kidan, Glycophene) is an example of a commercially used fungicide [61]. Because of their unique features, some glycofuranosylidene- and glycopyranosylidene-spiro-hydantoins have received wide attention. For example, (+)-hydantocidin (D-ribofuranosylidene-spiro-hydantoin) [62,63][62][63] possesses significant herbicidal and plant growth regulatory activities [41,64,65,66][41][64][65][66]; glucopyranosylidene-spiro-hydantoin [36,67,68][36][67][68] is among the most potent inhibitors of rabbit muscle glycogen phosphorylase known to date (Ki = 3–4 µM).
Figure 1. Therapeutically applied hydantoin derivatives.
Additionally, hydantoins also serve as key precursors in the chemical or enzymatic synthesis of significant nonnatural α-amino acids and their conjugates with medical potential. In this respect, the Bucherer–Bergs reaction provides an efficient method in the synthesis of important natural products as well as for the preparation of new organic compounds applicable as potential therapeutics.
Until now, five relevant reviews [69,70,71,72,73][69][70][71][72][73] and one book chapter [74] have appeared regarding the chemistry of hydantoins covering, inter alia, some aspects of the Bucherer–Bergs reaction. This review provides a comprehensive treatment of the synthesis of hydantoins via the Bucherer–Bergs reaction including the Hoyer modification but limited to free carbonyl compounds or carbonyl compounds protected as acetals (ketals) and cyanohydrins used as starting reaction components (i.e., the “classical” Bucherer–Bergs reaction starting from carbonyl compounds). The synthesis of hydantoins starting from corresponding amino nitriles (prepared from carbonyl compounds in a separate reaction step) or imines (prepared separately from carbonyl compounds or cyanides) were not included because, in this synthetic modification, only two reaction components are comprised, so these reactions are not multicomponent. Analogously, the other synthetic methods affording hydantoins were not reviewed in this review.

3. Conclusions

Although several synthetic methods for the preparation of hydantoins have been described so far, the Bucherer–Bergs reaction represents the simplest and very effective approach, in particular to 5-substituted and 5,5-disubstituted hydantoins (unsubstituted on N-1 and N-3). Therefore, this synthetic method is still current and often used for the synthesis of biologically and pharmacologically active compounds applicable in medicine, pharmacy, or agro-industry. In this respect, the presented review covered in depth the knowledge gained during the almost century-old history of hydantoin synthesis via the Bucherer–Bergs reaction.

References

  1. Bergs, H. Verfahren zur Darstellung von Hydantoinen. German Patent DE566094, 14 December 1932.
  2. Ciamician, G.; Silber, P. Chemische Lichtwirkungen. Ber. Dtsch. Chem. Ges. 1905, 38, 1671–1675.
  3. Bucherer, H.T.; Steiner, W. Syntheses of hydantoins. I. On reactions of α-hydroxy and α-amino nitriles. J. Prakt. Chem. 1934, 140, 291–316.
  4. Bucherer, H.T.; Fischbeck, H.T. Hexahydrodiphenylamine and its derivatives. J. Prakt. Chem. 1934, 140, 69–89.
  5. Bucherer, H.T.; Lieb, V.A. Syntheses of hydantoins. II. Formation of substituted hydantoins from aldehydes and ketones. J. Prakt. Chem. 1934, 141, 5–43.
  6. Henze, H.R.; Long, L.M. Researches on phenylhydantoins. J. Am. Chem. Soc. 1941, 63, 1936–1938.
  7. Henze, H.R.; Long, L.M. 5-(4-Biphenylyl)-5-R-hydantoins and bis-5-[(4-phenyl)-5-R-hydantoin]s. J. Am. Chem. Soc. 1941, 63, 1941–1943.
  8. Li, J.; Li, L.; Li, T.; Li, H.; Liu, J. An efficient and convenient procedure for the synthesis of 5,5-disubstituted hydantoins under ultrasound. Ultrason. Sonochem. 1996, 3, S141–S143.
  9. Hoyer, H.L. Über das camphan-2-spiro-hydantoin. Chem. Ber. 1950, 83, 491–500.
  10. Henze, H.R.; Speer, R.J. Identification of carbonyl compounds through conversion into hydantoins. J. Am. Chem. Soc. 1942, 64, 522–523.
  11. Oh, C.-H.; Kim, H.J.; Hong, S.-Y.; Lee, Y.-H.; Cho, J.K.; Cho, J.-H. New 1β-methylcarbapenems having a hydantoin moiety. Neue 1β-methylcarbapeneme mit hydantoin-substitution. Arch. Pharm. 1995, 328, 385–387.
  12. Marchand-Brynaert, J.; Arnadei, E.; Ghosez, L. Functionalized hydantoins as potential antibiotics. Bull. Soc. Chim. Belg. 1994, 103, 213–218.
  13. Oliveira, S.M.; Silva, J.B.P.; Hernandes, M.Z.; Lima, M.C.A.; Galdino, S.L.; Pitta, I.R. Structure, reactivity, and biological properties of hidantoines. Quim. Nova 2008, 31, 614–622.
  14. Ali, O.M.; Amer, H.H.; Mosaad, A.A.; Abdel-Rahman, A.A.-H. Synthesis and antimicrobial activity of new phenytoin derivatives and their acyclic nucleoside analogs. Chem. Heterocycl. Compd. 2012, 48, 1043–1049.
  15. Ali, O.M.; El-Sayed, W.A.; Eid, S.A.; Abdelwahed, N.A.M.; Abdel-Rahman, A.A.-H. Antimicrobial activity of new synthesized [(oxadiazolyl)methyl]phenytoin derivatives. Acta Polon. Pharm. 2012, 69, 657–667.
  16. Kim, D.; Wang, L.; Caldwell, C.G.; Chen, P.; Finke, P.E.; Oates, B.; MacCoss, M.; Mills, S.G.; Malkowitz, L.; Gould, S.L.; et al. Discovery of human CCR5 antagonists containing hydantoins for the treatment of HIV-1 infection. Bioorg. Med. Chem. Lett. 2001, 11, 3099–3102.
  17. Verlinden, Y.; Cuconati, A.; Wimmer, E.; Rombaut, B. The antiviral compound 5-(3,4-dichlorophenyl) methylhydantoin inhibits the post-synthetic cleavages and the assembly of poliovirus in a cell-free system. Antivir. Res. 2000, 48, 61–69.
  18. El-Barbary, A.A.; Khodair, A.I.; Pedersen, E.B.; Nielsen, C. S-Glucosylated hydantoins as new antiviral agents. J. Med. Chem. 1994, 37, 73–77.
  19. Anderson, J. The role of antiandrogen monotherapy in the treatment of prostate cancer. BJU Int. 2003, 91, 455–461.
  20. Kassouf, W.; Tanguay, S.; Aprikian, A.G. Nilutamide as second line hormone therapy for prostate cancer after androgen ablation fails. J. Urol. 2003, 169, 1742–1744.
  21. Struck, R.F.; Kirk, M.C.; Rice, L.S.; Suling, W.J. Isolation, synthesis and antitumor evaluation of spirohydantoin aziridine, a mutagenic metabolite of spirohydantoin mustard. J. Med. Chem. 1986, 29, 1319–1321.
  22. Nakabayashi, M.; Regan, M.M.; Lifsey, D.; Kantoff, P.W.; Taplin, M.-E.; Sartor, O.; Oh, W.K. Efficacy of nilutamide as secondary hormonal therapy in androgen-independent prostate cancer. BJU Int. 2005, 96, 783–786.
  23. Ciechanowicz-Rutkowska, M.; Stadnicka, K.; Kiec-Kononowicz, K.; Byrtus, H.; Filipek, B.; Zygmunt, M.; Maciag, D. Structure-activity relationship of some new anti-arrhythmic phenytoin derivatives. Arch. Pharm. 2000, 333, 357–364.
  24. Kieć-Kononowicz, K.; Stadnicka, K.; Mitka, A.; Pekala, E.; Filipek, B.; Sapa, J.; Zygmunt, M. Synthesis, structure and antiarrhythmic properties evaluation of new basic derivatives of 5,5-diphenylhydantoin. Eur. J. Med. Chem. 2003, 38, 555–566.
  25. Knabe, J.; Baldauf, J.; Ahlhem, A. Racemates and enantiomers of basic substituted 5-phenylhydantoins. Syntheses and antiarrhythmic activity. (Razemate und enantiomere basisch substituierter 5-phenylhydantoine, synthese und antiarrhythmische wirkung). Pharmazie 1997, 52, 912–919.
  26. Matsukura, M.; Daiku, Y.; Ueda, K.; Tanaka, S.; Igarashi, T.; Minami, N. Synthesis and antiarrhythmic activity of 2,2-dialkyl-1′-(N-substituted aminoalkyl)-spiro-[chroman-4,4′-imidazolidine]-2′,5′-diones. Chem. Pharm. Bull. 1992, 40, 1823–1827.
  27. Thenmozhiyal, J.C.; Wong, P.T.-H.; Chui, W.-K. Anticonvulsant activity of phenylmethylenehydantoins: A structure–activity relationship study. J. Med. Chem. 2004, 47, 1527–1535.
  28. LeTiran, J.; Stables, J.P.; Kohn, H. Functionalized amino acid anticonvulsants: Synthesis and pharmacological evaluation of conformationally restricted analogues. Bioorg. Med. Chem. 2001, 9, 2693–2708.
  29. Anger, T.; Madge, D.J.; Mulla, M.; Riddall, D. Medicinal chemistry of neuronal voltage-gated sodium channel blockers. J. Med. Chem. 2001, 44, 115–137.
  30. Scholl, S.; Koch, A.; Henning, D.; Kempter, G.; Kleinpeter, E. The influence of structure and lipophilicity of hydantoin derivatives on anticonvulsant activity. Struct. Chem. 1999, 10, 355–366.
  31. Brouillette, W.J.; Jestkov, V.P.; Brown, M.L.; Akhtar, M.S.; DeLorey, T.M.; Brown, G.B. Bicyclic hydantoins with a bridgehead nitrogen. Comparison of anticonvulsant activities with binding to the neuronal voltage-dependent sodium channel. J. Med. Chem. 1994, 37, 3289–3293.
  32. Kwon, C.H.; Iqbal, M.T.; Wurpel, J.N.D. Synthesis and anticonvulsant activity of 2-iminohydantoins. J. Med. Chem. 1991, 34, 1845–1849.
  33. Botros, S.; Khalil, N.A.; Naguib, B.H.; El-Dash, Y. Synthesis and anticonvulsant activity of new phenytoin derivatives. Eur. J. Med. Chem. 2013, 60, 57–63.
  34. Deodhar, M.; Sable, P.; Bhosale, A.; Juvale, K.; Dumbare, R.; Sakpal, P. Synthesis and evaluation of phenytoin derivatives as anticonvulsant agents. Turk. J. Chem. 2009, 33, 367–373.
  35. Edmunds, J.J.; Klutchko, S.; Hamby, J.M.; Bunker, A.M.; Connolly, C.J.C.; Winters, R.T.; Quin III, J.; Sircar, I.; Hodges, J.C.; Panek, R.L.; et al. Derivatives of 5-[[1-4(4-carboxybenzyl)imidazolyl]methylidene]hydantoins as orally active angiotensin II receptor antagonists. J. Med. Chem. 1995, 38, 3759–3771.
  36. Somsák, L.; Kovács, L.; Tóth, M.; Ösz, E.; Szilágyi, L.; Györgydeák, Z.; Dinya, Z.; Docsa, T.; Tóth, B.; Gergely, P. Synthesis of and a comparative study on the inhibition of muscle and liver glycogen phosphorylases by epimeric pairs of D-gluco- and D-xylopyranosylidene-spiro-(thio)hydantoins and N-(D-glucopyranosyl) amides. J. Med. Chem. 2001, 44, 2843–2848.
  37. Oka, M.; Matsumoto, Y.; Sugiyama, S.; Tsuruta, N.; Matsushima, M. A potent aldose reductase inhibitor, (2S,4S)-6-fluoro-2′,5′-dioxospiro[chroman-4,4′-imidazolidine]-2-carboxamide (Fidarestat): Its absolute configuration and interactions with the aldose reductase by X-ray crystallography. J. Med. Chem. 2000, 43, 2479–2483.
  38. Murakami, N.; Ohta, M.; Kato, K.; Nakayama, K.; Mizota, M.; Miwa, I.; Okuda, J. Effects of 1-(3-bromobenzofuran-2-ylsulfonyl)hydantoin on human aldose reductase examined by a new application of HPLC system for measuring tissue polyol. Arzneimittelforschung/Drug Res. 1997, 47, 1222–1225.
  39. Sarges, R.; Oates, P.J. Aldose reductase inhibitors: Recent developments. Prog. Drug Res. 1993, 40, 99–161.
  40. Haruyama, H.; Takayama, T.; Kinoshita, T.; Kondo, M.; Nakajima, M.; Haneishi, T. Structural elucidation and solution conformation of the novel herbicide hydantocidin. J. Chem. Soc. Perkin Trans. 1 1991, 1637–1640.
  41. Siehl, D.L.; Subramanian, M.V.; Walters, E.W.; Lee, S.F.; Anderson, R.J.; Toschi, A.G. Adenylosuccinate synthetase: Site of action of hydantocidin, a microbial phytotoxin. Plant. Physiol. 1996, 110, 753–758.
  42. Heim, D.R.; Gerwick, B.C.; Murdoch, M.G.; Green, S.B. Hydantocidin: A possible proherbicide inhibiting purine biosynthesis at the site of adenylosuccinate synthetase. Pest. Biochem. Physiol. 1995, 53, 138–145.
  43. Mizuno, T.; Kino, T.; Takatoshi, I.; Miyata, T. Synthesis of aromatic urea herbicides by the selenium-assisted carbonylation using carbon monoxide with sulfur. Synth. Commun. 2000, 30, 1675–1688.
  44. Fischer, H.-P.; Buser, H.-P.; Chemla, P.; Huxley, P.; Lutz, W.; Mirza, S.; Tombo, G.M.R.; van Lommen, G.; Sipido, V. Synthesis and chirality of novel heterocyclic compounds designed for crop protection. Bull. Soc. Chim. Belg. 1994, 103, 565–581.
  45. Sano, H.; Sugai, S. Synthesis of (±)-carbocyclic analogue of spirohydantoin nucleoside. Tetrahedron 1995, 51, 4635–4646.
  46. Bazil, C.W. Sleep, sleep apnea, and epilepsy. Curr. Treat. Options Neurol. 2004, 6, 339–345.
  47. Bosch, J.; Roca, T.; Domènech, J.; Suriol, M. Synthesis of water-soluble phenytoin prodrugs. Bioorg. Med. Chem. Lett. 1999, 9, 1859–1862.
  48. Bac, P.; Maurois, P.; Dupont, C.; Pages, N.; Stables, J.P.; Gressens, P.; Evrard, P. Magnesium deficiency-dependent audiogenic seizures (MDDASs) in adult mice: A nutritional model for discriminatory screening of anticonvulsant drugs and original assessment of neuroprotection properties. J. Neurosci. 1998, 18, 4363–4373.
  49. Krall, R.L.; Penry, J.K.; White, B.G.; Kupferberg, H.J.; Swinyard, E.A. Antiepileptic drug development: II. Anticonvulsant drug screening. Epilepsia 1978, 19, 409–428.
  50. Reagan, L.P.; McKittrick, C.R.; McEwen, B.S. Corticosterone and phenytoin reduce neuronal nitric oxide synthase messenger RNA expression in rat hippocampus. Neuroscience 1999, 91, 211–219.
  51. Taylor, C.P. Voltage-gated Na+ channels as targets for anticonvulsant, analgesic and neuroprotective drugs. Curr. Pharm. Des. 1996, 2, 375–388.
  52. Eadie, M.J. Phenytoin. In The Treatment of Epilepsy, 2nd ed.; Shorvon, S., Perucca, E., Fish, D., Dodson, E., Eds.; Blackwell Publishing: Oxford, UK, 2004; pp. 475–488.
  53. Brendstrup, L.; Hjelt, K.; Petersen, K.E.; Petersen, S.; Andersen, E.A.; Daugbjerg, P.S.; Stagegaard, B.R.; Nielsen, O.H.; Vejlsgaard, R.; Schou, G.; et al. Nitrofurantoin versus trimethoprim prophylaxis in recurrent urinary tract infection in children. A randomized, double-blind study. Acta Paediatr. Scand. 1990, 79, 1225–1234.
  54. D’Arcy, P.F. Nitrofuratoin. Drug Intell. Clin. Pharm. 1985, 19, 540–547.
  55. Richards, W.A.; Riss, E.; Kass, E.H.; Finland, M. Nitrofurantoin: Clinical and laboratory studies in urinary tract infections. AMA Arch. Intern. Med. 1955, 96, 437–450.
  56. Sarges, R.; Howard, H.R.; Kelbaugh, P.R. Synthesis of optically active spirohydantoins by asymmetric induction. Hydantoin formation from amino nitriles and chlorosulfonyl isocyanate. J. Org. Chem. 1982, 47, 4081–4085.
  57. Cohen, R.A.; Hennekens, C.H.; Christen, W.G.; Krolewski, A.; Nathan, D.M.; Peterson, M.J.; LaMotte, F.; Manson, J.E. Determinants of retinopathy progression in type 1 diabetes mellitus. Am. J. Med. 1999, 107, 45–51.
  58. Schmidt, R.E.; Plurad, S.B.; Coleman, B.D.; Williamson, J.R.; Tilton, R.G. Effects of sorbinil, dietary myo-inositol supplementation, and insulin on resolution of neuroaxonal dystrophy in mesenteric nerves of streptozocin-induced diabetic rats. Diabetes 1991, 40, 574–582.
  59. Krause, T.; Gerbershagen, M.U.; Fiege, M.; Weisshorn, R.; Wappler, F. Dantrolene—A review of its pharmacology, therapeutic use and new developments. Anaesthesia 2004, 59, 364–373.
  60. Dorian, P.; Borggrefe, M.; Al-Khalidi, H.R.; Hohnloser, S.H.; Brum, J.M.; Tatla, D.S.; Brachmann, J.; Myerburg, R.J.; Cannom, D.S.; van der Laan, M.; et al. Placebo-controlled, randomized clinical trial of azimilide for prevention of ventricular tachyarrhythmias in patients with an implantable cardioverter defibrillator. Circulation 2004, 110, 3646–3654.
  61. Lacroix, L.; Laurent, M.; Buys, M. Iprodione. In Analytical Methods for Pesticides and Plant Growth Regulators: Vol. II.; Zweig, G., Sherma, J., Eds.; Academic Press: London, UK, 1980; pp. 247–261.
  62. Shiozaki, M. Synthesis of hydantocidin and C-2-thioxo-hydantocidin. Carbohydr. Res. 2001, 335, 147–150.
  63. Shiozaki, M. Syntheses of hydantocidin and C-2-thioxohydantocidin. Carbohydr. Res. 2002, 337, 2077–2088.
  64. Renard, A.; Lhomme, J.; Kotera, M. Synthesis and properties of spiro nucleosides containing the barbituric acid moiety. J. Org. Chem. 2002, 67, 1302–1307.
  65. Walter, M.W. Structure-based design of agrochemicals. Nat. Prod. Rep. 2002, 19, 278–291.
  66. Nakajima, M.; Itoi, K.; Takamatsu, Y.; Kinoshita, T.; Okazaki, T.; Kawakubo, K.; Shindo, M.; Honma, T.; Tohjigamori, M.; Haneishi, T. Hydantocidin: A new compound with herbicidal activity from Streptomyces hygroscopicus. J. Antibiot. 1991, 44, 293–300.
  67. Bichard, C.J.F.; Mitchel, E.P.; Wormald, M.R.; Watson, K.A.; Johnson, L.N.; Zographos, S.E.; Koutra, D.D.; Oikonomakos, N.G.; Fleet, G.W.J. Potent inhibition of glycogen phosphorylase by a spirohydantoin of glucopyranose: First pyranose analogues of hydantocidin. Tetrahedron Lett. 1995, 36, 2145–2148.
  68. Ösz, E.; Somsák, L.; Szilágyi, L.; Kovács, L.; Docsa, T.; Tóth, B.; Gergely, P. Efficient inhibition of muscle and liver glycogen phosphorylases by a new glucopyranosylidene-spiro-thiohydantoin. Bioorg. Med. Chem. Lett. 1999, 9, 1385–1390.
  69. Ware, E. The chemistry of the hydantoins. Chem. Rev. 1950, 46, 403–470.
  70. Bateman, J.H. Hydantoin and derivatives. In Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed.; Grayson, M., Eckroth, D., Eds.; Wiley-Interscience: New York, NY, USA, 1980; Volume 12, pp. 692–711.
  71. López, C.A.; Trigo, G.G. The chemistry of hydantoins. Adv. Heterocycl. Chem. 1985, 38, 177–228.
  72. Meusel, M.; Gütschow, M. Recent developments in hydantoin chemistry: A review. Org. Prep. Proced. Int. 2004, 36, 391–443.
  73. Konnert, L.; Lamaty, F.; Martinez, J.; Colacino, E. Recent advances in the synthesis of hydantoins: The state of the art of a valuable scaffold. Chem. Rev. 2017, 117, 13757–13809.
  74. Marqués-López, E.; Herrera, R.P. Bucherer–Bergs and Strecker multicomponent reactions. In Multicomponent Reactions: Concepts and Applications for Design and Synthesis; Herrera, R.P., Marqués-López, E., Eds.; John Wiley & Sons: Hoboken, NJ, USA, 2015; pp. 331–357.
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