o-Iodoxybenzoic Acid Mediated Oxidative Desulfurization of 1,3-Disubstituted Thioureas to Carbodiimides

Abstract

An efficient and mild oxidative desulfurization procedure using o-iodoxybenzoic acid has been developed for the synthesis of carbodiimides starting from easily synthesizable 1,3-disubstituted thioureas.

Key words

o-iodoxybenzoic acid - oxidation - desulfurization - thiourea - carbodiimide

References and Notes

• 1 Wang SS. Tam JP. Wang BSH. Merrifield RB. Int. J. Pept. Protein Res.  1981,  19:  459 
• 2 Narang SA. Tetrahedron  1983,  3:  39 
• 3a Zhang WX. Li D. Wang Z. Xi Z. Organometallics  2009,  28:  882 
• 3b Lv X. Bao W. J. Org. Chem.  2009,  74:  5618 
• 3c Olimpieri F. Volonterio A. Zanda M. Synlett  2008,  882 
• 3d Mikolajczyk M. Kielbasinski P. Tetrahedron  1981,  32:  233 
• 3e Kurzer F. Douraghi-Zaden K. Chem. Rev.  1967,  67:  107 
• 3f Khorana HG. Chem. Rev.  1953,  53:  145 
• 4 Knox JR. Toia RF. Casida JE. J. Agric. Food. Chem.  1992,  40:  909 
• 5 Molina P. Alajarin MM. Vidal A. Sanchez-Andrada P. J. Org. Chem.  1992,  57:  929 
• 6 Tucker B, and Ulrich H. inventors; US  3345407. 
• 7a Rahman AKF. Nicholas KM. Tetrahedron Lett.  2007,  48:  6002 
• 7b Barbaro G. Battaflia A. Giorgianni P. Guterrini A. Scooni G. J. Org. Chem.  1995,  60:  6032 
• 7c Tang J. Mohan T. Verkade JG. J. Org. Chem.  1994,  59:  4931 
• 7d Bryan JC. Rheingold AL. Geib SJ. Meyer JM. J. Am. Chem. Soc.  1987,  109:  2826 
• 7e Deeming AJ. Hardcastle K. Fuchita Y. Henrick K. Mcpartlin MJ. J. Chem. Soc., Dalton Trans.  1986,  2259 
• 8a Zhang M. Vedantham P. Flynn DL. Hanson PR. J. Org. Chem.  2004,  69:  8340 
• 8b Fell JB. Coppola GM. Synth. Commun.  1999,  25:  43 
• 8c Schlama T. Gouverneur V. Mioskowski C. Tetrahedron Lett.  1996,  37:  7047 
• 8d Hessel ET. Jones WD. Organometallics  1992,  11:  1496 
• 9a Isobe T. Ishikawa T. J. Org. Chem.  1999,  64:  6984 
• 9b Fell JB. Coppola GM. Synth. Commun.  1995,  25:  43 
• 9c Jae IL. Bull. Korean Chem. Soc.  1995,  16:  1143 
• 9d Kim S. Yi KY. Tetrahedron Lett.  1986,  27:  1925 
• 9e Kim S. Yi KY. J. Org. Chem.  1986,  51:  2613 
• 9f Kim S. Yi KY. Tetrahedron Lett.  1985,  26:  1661 
• 9g Fujinami FL. Otani N. Sakai S. Synthesis  1977,  889 
• 9h Mitsunobu O. Kato K. Tomari M. Tetrahedron  1970,  26:  5731 
• 9i Mitsunobu O. Kato K. Kakese F. Tetrahedron Lett.  1969,  2473 
• 9j Ulrich H. Sayigh AAR. Angew. Chem., Int. Ed. Engl.  1966,  5:  704 
• 9k Sheehan JC. Hlavka JJ. J. Am. Chem. Soc.  1957,  79:  4528 
• 9l Bortnick N. Luskin LS. Hurwitz MD. Rytina AW. J. Am. Chem. Soc.  1956,  78:  4358 
• 10 Ali RA. Ghosh H. Patel BK. Tetrahedron Lett.  2010,  51:  1019 
• 11a Zhdankin VV. ARKIVOC  2009,  (i):  1 
• 11b Zhdankin VV. Stang PJ. Chem. Rev.  2008,  108:  5299 
• 11c Ladziata U. Zhdankin VV. ARKIVOC  2006,  (ix):  26 
• 11d Shukla VG. Salgoankar PD. Akamanchi KG. Synlett  2005,  1483 
• 11e Nicolaou KC. Mathison CJN. Montagnon T. Angew. Chem. Int. Ed.  2003,  42:  4077 
• 11f Shukla VG. Salgoankar PD. Akamanchi KG. J. Org. Chem.  2003,  68:  5422 
• 11g Krishnaveni NS. Surendra K. Rao NKR. Synthesis  2003,  2295 
• 11h Zhdankin VV. Stang PJ. Chem. Rev.  2002,  102:  2523 
• 11i Nicolaou KC. Montagnon T. Baran PS. Angew. Chem. Int. Ed.  2002,  41:  993 
• 11j Nicolaou KC. Gray DLF. Montagnon T. Harrison ST. Angew. Chem. Int. Ed.  2002,  41:  996 
• 12a Deshmukh SS. Huddar SN. Bhalerao DS. Akamanchi KG. ARKIVOC  2010,  (ii):  118 
• 12b Patil PC. Bhalerao DS. Dangate PS. Akamanchi KG. Tetrahedron Lett.  2009,  50:  5820 
• 12c Bellale EV. Bhalerao DS. Akamanchi KG. J. Org. Chem.  2008,  73:  7324 
• 12d Bhalerao DS. Mahajan US. Chaudhari KH. Akamanchi KG. J. Org. Chem.  2007,  73:  662 
• 12e Arote ND. Bhalerao DS. Akamanchi KG. Tetrahedron Lett.  2007,  48:  3651 
• 12f Chaudhari KH. Mahajan US. Bhalerao DS. Akamanchi KG. Synlett  2007,  2815 
• 13 Singh CB. Ghosh H. Murru S. Patel BK. J. Org. Chem.  2008,  73:  2924 
• 14 Williams A. Ibrahim IJ. Chem. Rev.  1981,  81:  589 

15

Typical Procedure
Preparation of 1,3-Diphenyl Carbodiimide 2a
To a stirred solution of IBX (0.6 g, 2.19 mmol) and Et₃N (0.6 mL, 4.38 mmol) in dry CH₂Cl₂ (10 mL) at 0 ˚C was added 1,3-diphenylthiourea (0.5 g, 2.19 mmol) portionwise over a period of 5 min. After completion of reaction, as indicated by TLC, reaction mixture was concentrated under vacuum, and the residue was extracted with hexane (2 × 15 mL). Pure product was isolated after evaporation of the hexane extract followed by column chromatography (SiO₂, 60-120 mesh, eluent: hexane). Yield 0.38 g (90%), oily liquid. ^¹H NMR (300 MHz, CDCl₃): δ = 7.20 (m, 6 H), 7.31 (m, 4 H). ^¹³C NMR (75 MHz, CDCl₃): δ = 124, 125.2, 129.2, 136.2, 138.4. IR (KBr): 2140, 2110 cm^-¹. All synthesized compounds are known compounds. Characterization data are provided as Supporting Information.