Synlett 2015; 26(07): 960-964
DOI: 10.1055/s-0034-1380127
letter
© Georg Thieme Verlag Stuttgart · New York

Facile Synthesis of Methanofullerenes in an Aqueous Two-Phase System under Photoirradiation Conditions

Toshiyuki Iwai*
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Fukashi Matsumoto
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Koichi Hida
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Kazuyuki Moriwaki
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Yuko Takao
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Takatoshi Ito
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Takumi Mizuno
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
,
Toshinobu Ohno*
Osaka Municipal Technical Research Institute, 1-6-50, Morinomiya, Joto-ku, Osaka 536-8553, Japan   Email: iwai@omtri.or.jp   Email: ohno@omtri.or.jp
› Author Affiliations
Further Information

Publication History

Received: 27 November 2014

Accepted after revision: 06 January 2015

Publication Date:
10 February 2015 (online)


Abstract

Methanofullerenes, such as [6,6]-phenyl-C61-butyric acid methyl ester {[6,6]PC61BM (1a)}, were synthesized in good yields from the corresponding tosylhydrazones in an aqueous two-phase (o-dichlorobenzene–H2O) system under photoirradiation conditions. This simple and convenient procedure was adopted for the synthesis of thienyl analogues of PC61BM and its C70 analogue, PC71BM.

 
  • References and Notes

  • 2 Hummelen JC, Knight BW, LePeq F, Wudl F, Yao J, Wilkins CL. J. Org. Chem. 1995; 60: 532
  • 3 Shaheen SE, Brabec CJ, Sariciftci NS, Padinger F, Fromherz T, Hummelen JC. Appl. Phys. Lett. 2001; 78: 841
  • 4 Service RF. Science 2011; 332: 293
  • 10 Authors supposed trace amount of H2O caused poor reproducibility of the original Hummelen’s procedure2 owing to degradation of NaOMe and precipitation of NaOH from reaction media.
  • 11 Janssen RA. J, Hummelen JC, Wudl F. J. Am. Chem. Soc. 1995; 117: 544
    • 13a Ruoff RS, Tse DS, Malhotra R, Lorents DC. J. Phys. Chem. 1993; 97: 3379
    • 13b Scrivens WA, Tour JM. J. Chem. Soc., Chem. Commun. 1993; 1207
  • 14 Jończyk A, Włostowska J, Mąkosza M. Tetrahedron 2001; 57: 2827
  • 15 Li J, Takeuchi A, Ozawa M, Li X, Saigo K, Kitazawa K. J. Chem. Soc., Chem. Commun. 1993; 1784
  • 16 When an excess amount of tosylhydrazone was used, higher adducts, such as trisadducts, were detected.
  • 17 General Procedure for the Synthesis of Methanofullerenes under Photoirradiation Conditions Under Ar atmosphere, to a solution of tosylhydrazone (18.7 mg, 0.050 mmol) in ODCB (2.0 mL) was added a solution of TBAH (1.0 M in H2O, 0.05 mL, 0.050 mmol) in H2O (1.95 mL), and the mixture was stirred at r.t. for 0.5 h. A solution of C60 (36.0 mg, 0.050 mmol) in ODCB was added to the mixture, and the mixture was stirred (800–1000 rpm by magnetic stirrer), heated in an oil bath, and irradiated with a 375 W incandescent lamp for 2 h. During the irradiation, the oil bath temperature was kept at 105–115 °C by adjusting the distance between the light source and the flask was approximately 15 cm. After the reaction, the layers were separated and the aqueous phase was extracted with toluene (2 × 5 mL). The combined organic phase was dried over MgSO4, filtered, and concentrated to 1 mL under reduced pressure. The residue was purified by silica gel column chromatography [silica gel; 20 g, eluent; toluene for C60 and monoadduct, toluene–CH2Cl2 (1:2) for bisadducts], and the obtained [6,6]PC61BM (1a) was dissolved in a small amount of toluene and transferred to a 50 mL centrifuge tube. MeOH (ca. 30 mL) was added, and the mixture was immersed in an ultrasound bath for 1 min, the suspension was centrifuged (4000 rpm, 30 min), the supernatant was decanted, and the residue was treated with MeOH in the same manner. The product was dried in vacuo at 60 °C. [6,6]PC61BM (1a, 23.5 mg, 0.026 mmol, 52%) was obtained as brown powder. Unreacted C60 (7.8 mg, 0.011 mmol, 22%) and bisadducts (10.9 mg, 0.010 mmol, 20%) were isolated in the same manner. Analytical Data for 1a 1H NMR (300 MHz, CDCl3): δ = 7.92 (d, J = 8.7 Hz, 2 H), 7.60–7.44 (m, 3 H), 3.68 (s, 3 H), 2.94–2.88 (m, 2 H), 2.52 (t, J = 7.5 Hz, 2 H), 2.23–2.13 (m, 2 H). 13C NMR (75 MHz, CDCl3): δ = 173.40, 148.79–136.71, 132.06, 128.43, 128.24, 79.87, 51.85, 51.64, 33.87, 33.67, 22.37. IR (KBr): 2921, 2849, 1735, 699, 573, 550, 526, 482, 453 cm–1. MS (MALDI): m/z calcd for C72H14O2: 910.1; found: 910.1 [M].

    • A few pieces of research for the synthesis of methanofullerenes using flow synthesis have been reported:
    • 18a Seyler H, Wong WH, Holmes AB. J. Org. Chem. 2011; 76: 3551
    • 18b Rossi E, Carofiglio T, Venturi A, Ndobe A, Muccini M, Maggini M. Energy Environ. Sci. 2010; 4: 725