Supporting information

Gelation Properties of Poly(aryl ether) dendrons bearing long alkyl chains

Tomoaki Ando and Kazuaki Ito*

Department of Chemistry and Chemical Engineering, Graduate School of Science and Engineering, Yamagata University, Jhonan 4-3-16, Yonezawa, 992-8510 JAPAN

Synthesis of methyl 3,4,5-trihydroxy benzoate (3).[1]

A mixture of 3,4,5-trihydroxy benzoic acid (10.0 g, 58.8 mmol), conc sulfuric acid (4.61 g, 47.1mmol) and dry methanol (87 ml) was heated at 60 C for 24 h. After cooling to r.t., removal of solvent gave solid residue, which was dissolved with ethyl acetate. The solution was washed with water several times and the organic layer was dried over anhydrous sodium sulfate. Removal of solvent gave 3(6.40 g, 64 % yield) as white crystals.

3: 78% yield, white crystals.mp 120-124 C.

1H-NMR (DMSO-d6):3.71(s,CO2CH3, 3H), 6.90(s,Ar-H,2H), 10.0 (bs, OH, 3H).

.

Synthesis of methyl 3,4,5-tris(n-alkyl-1-yloxy) benzoate (1a8and 1a12). [2]

To a mixture of methyl 3,4,5-trimethoxy benzoate (3) (5.00 g, 27.2mmol), potassium carbonate (22.5 g, 163mmol) and DMF (133 ml) was added 1-bromooctane (21.0 g, 109 mmol) over 5 min under nitrogen atmosphere. After the addition was completed, the mixture was heated at 60 C for 12 h. After cooling to r. t., the reaction mixture was poured into the ice-water and then extracted with chloroform. The organic layer was separated and dried over anhydrous sodium sulfate. Removal of the solvent gave oily residue, which was subjected column chromatography on alumina using dichloromethane as an eluent to give colorless oil. The oil was further subjected to column chromatography on silica gel using hexane / ethyl acetate (10/1, v/v) as an eluent to give 1a8 (11.3 g, 80 % yield) as oil. The analogous compound (1a12) was obtained the similar reaction procedure by using 1-buromododecaneas a starting material instead of 1-bromooctane.

1a8:80 % yield. 1H-NMR (CDCl3):0.87 (t, CH3 x 3,J=7.2Hz, 9H), 1.20-1.38(bs, CH2 x 12, 24H),1.46 (m,CH2 x 3, 6H), 1.73 (quintet, CH2, J = 8.0 Hz, 2H), 1.80(quintet, CH2 x 2, 4H, J = 7.6 Hz),3.88(s,CO2CH3, 3H),4.00(t, CH2OAr x 3, J=6.8Hz, 6H),7.24,(s,Ar-H, 2H).

1a12:84 % yield. 1H-NMR (CDCl3):0.87 (t,CH3 x 3, J=7.2Hz, 9H), 1.20-1.38(bs,CH2 x 24, 48H),1.46 (m, CH2 x 3, 6H), 1.73 (quintet, CH2, J = 8.0 Hz, 2H), 1.80(quintet, CH2 x 2, 4H, J = 7.6 Hz), 3.88(s, CO2CH3, 3H), 4.00(t, CH2OAr x 3, J = 6.8Hz, 6H),7.24,(s, Ar-H, 2H).

Synthesis of 3,4,5-tris(n-alkyl-1-yloxy) benzoate (1b8 and 1b12).[3]

A mixture of 1a8 (1.5g、2.88mmol) and potassium hydroxide (1.13g, 20.2mmol) in ethanol (15ml) was refluxed for 3 . After cooling to room temperature, the reaction mixture was acidified by 10% HCl aqueous solution in an ice-bath. The precipitate was collected by filtration and then dried in vacuo. 1b8 was obtained in 80 % yield (1.17 g) as white crystals. The analogous compound (1b12) was obtained the similar reaction procedure by using 1a12as a starting material instead of 1a8.

1b8: 80 % yield.1H-NMR (CDCl3): 0.87 (t, CH3 x 3, J = 7.2 Hz, 9H), 1.20-1.38 (bs, CH2 x 12, 24H), 1.46 (m, CH2 x 3, 6H), 1.73 (quintet, CH2, J = 7.6 Hz, 2H), 1.80(quintet, CH2 x 2, 4H, J = 7.6 Hz), 4.01 (t, CH2OAr x 2, J = 6.4 Hz, 4H), 4.03 (t, CH2OAr, J = 6.4 Hz, 2H), 7.24,(s, Ar-H, 2H).

1b12: 71 % yield.1H-NMR (CDCl3):0.87 (t,CH3 x 3, J=7.2Hz, 9H), 1.20-1.38(bs,CH2 x 24, 48H),1.46 (m, CH2 x 3, 6H), 1.73 (quintet, CH2, J = 7.6 Hz, 2H), 1.80(quintet, CH2 x 2, 4H, J = 7.6 Hz), 3.88(s, CO2CH3, 3H), 4.01 (t, CH2OAr x 2, J = 6.4 Hz, 4H) , 4.03(t, CH2OAr, J = 6.6 Hz, 2H),7.24,(s, Ar-H, 2H).

Synthesis of 3,4,5-tris(n-alkyl-1-yloxy) benzyl alcohol (4).[3]

A solution of 1a8 (3.44 g, 6.61 mmol) in dry ether (8 ml) was added dropwise to a suspension of lithium aluminum hydride (188 mg, 4.96 mmol) in dry ether (4 ml). After the addition was completed, the mixture was allowed to stir at room temperature for 1 h. The reaction was quenched by dropwise, addition of 10% HCl aqueous solution in an ice-bath. The precipitate was rinsed with tetrahydrofuran. Undissolved materials were filter off. Organic layer was separated and dried over anhydrous sodium sulfate. Removal solvent gave white solid material, which was recrystallized from acetone to give 4a (2.91 g, 90 %) as white crystals.The analogous compound (4b) was obtained the similar reaction procedure by using 1a12as a starting material instead of 1a8.

4a: 90 % yield.1H-NMR (CDCl3):0.87 (t, CH3 x 3, J = 6.8 Hz, 9H), 1.20-1.38 (bs, CH2 x 12, 24H), 1.45 (m, CH2 x 3, 6H), 1.76 (m, CH2 x 3, 6H), 3.92(t, CH2OAr, J = 6.8Hz, 2H), 3.96 (t, CH2Oar x 2, J = 6.4 Hz, 4H), 4.59 (d, ArCH2OH, J = 6.0 Hz, 2H), 6.55 (s, Ar-H, 2H).

4b: 93 % yield.1H-NMR (CDCl3): 0.87 (t, CH3 x 3, J = 6.8 Hz, 9H), 1.20-1.38 (bs, CH2 x 24, 48H), 1.45 (m, CH2 x 3, 6H), 1.76 (m, CH2 x 3, 6H), 3.92 (t, CH2OAr, J = 6.8 Hz, 2H), 3.96 (t, CH2Oar x 2, J = 6.4 Hz, 4H), 4.59 (d, ArCH2OH, J = 6.0 Hz, 2H), 6.55 (s, Ar-H, 2H).

Synthesis of 3,4,5-tris(n-alkyl-1-yloxy) benzyl chloride (5). [3]

A solution of 4a (2.91 g, 5.91 mmol), thionyl chloride (982 mg, 8.27 mmol), and a catalytic amount of N,N-dimetylformamide (a drop) in dry dichloromethane (30 ml) was refluxed for 0.5 h. The solvent and excess thionyl chloride was removed under a reduced pressure. The solid residue was dissolved in ether, washed with water several times, dried over anhydrous sodium sulfate. Removal of solvent gave 5a (2.84 g, 94.4 %) as white crystals. The analogous compound (5b) was obtained the similar reaction procedure by using 4bas a starting material instead of 4a.

5a: 94 % yield. 1H-NMR (CDCl3):0.87 (t, CH3 x 3, J = 6.8 Hz, 9H), 1.20-1.38 (bs, CH2 x 12, 24H), 1.45 (m, CH2 x 3, 6H), 1.79 (m, CH2 x 3, 6H), 3.93(t, CH2OAr, J = 6.4Hz, 2H), 3.96 (t, CH2OAr x 2, J = 6.4 Hz, 4H), 4.50 (s, ArCH2Cl, 2H), 6.55 (s, Ar-H, 2H).

5b: 91 % yield.1H-NMR (CDCl3):0.87 (t, CH3 x 3, J = 6.8 Hz, 9H), 1.20-1.38 (bs, CH2 x 24, 48H), 1.45 (m, CH2 x 3, 6H), 1.79 (m, CH2 x 3, 6H), 3.93 (t, CH2OAr, J = 6.4 Hz, 2H), 3.96 (t, CH2OAr x 2, J = 6.4 Hz, 4H), 4.50 (s, ArCH2Cl, 2H), 6.55 (s, Ar-H, 2H).

Synthesis of Poly(aryl ether)dendrons (2a8and 2a12)[3]

5a (1.82 g, 3.57 mmol) was added to a suspension of 3 (219 mg, 1.19 mmol) and potassium carbonate (1.48 g, 10.7 mmol) in dry and degassed N,N-dimethyl formamide (36 ml) at 65 C. After the addition was completed, the mixture was heated at 65 for 3.5 h. The reaction mixture was poured into ice-water. The precipitate was collected and dissolved in dichloromethane. The solutionwas subjected column chromatography on alumina using dichloromethane as an eluent to give 2a8 (807 mg, 41.1% yield) as white crystals. The analogous compound (2a12) was obtained the similar reaction procedure by using 5bas a starting material instead of 5a.

2a8: 41 % yield. 1H-NMR (CDCl3): 0.87(t, CH3 x 9, J = 6.8 Hz, 27H),1.20-1.50(m, CH2 x 45, 90H), 1.72(m, CH2 x 9, 18 H),3.74(t,CH2OAr x 2, J = 6.4 Hz, 4H),3.87(t,CH2OAr x 4, J = 5.2 Hz, 8H), 3.87(s,CO2CH3, 3H),3.92(t,6H,CH2OAr x 3, J = 6.8 Hz, 6H), 5.02(s,ArCH2OAr,6H), 6.59(s,Ar-H, 2H),6.62(s,Ar-H, 4H), 7.37(s, Ar-H, 2H).

2a12: 69 % yield.1H-NMR (CDCl3): 0.87 (t, CH3 x 9, J = 6.8 Hz, 27H), 1.20-1.50(m, CH2 x 81, 162H), 1.72 (m, CH2 x 9, 18 H), 3.74 (t, CH2OAr x 2, J = 6.4 Hz, 4H), 3.87 (t, CH2OAr x 4, J = 5.2 Hz, 8H), 3.87(s,CO2CH3, 3H), 3.92 (t, 6H,CH2OAr x 3, J = 6.8 Hz, 6H), 5.02 (s, ArCH2OAr, 6H), 6.59 (s, Ar-H, 2H), 6.62 (s,Ar-H, 4H), 7.37 (s, Ar-H, 2H).

Synthesis of Poly(aryl ether)dendrons (2b8and 2b12)[3]

A mixture of 2a8 (100 mg, 0.616 mmol), 10N NaOH aqueous solution (1.0 ml) and rhtanol (10 ml) was heated at 80 C for 3h. After cooling to room temperature, the reaction mixture was acidified by 10% HCl aqueous solution in an ice-bath. The precipitate was collected by filtration and then dissolved in dichloromethane. The solution was dried over anhydrous sodium sulfate. Removal of solvent gave white crystals, which was recrystallized from ether to give 2b8 (41mg, 41 %) as white crystals.The analogous compound (2b12) was obtained the similar reaction procedure by using 2a12as a starting material instead of 2a8.

2b8: 41 % yield.1H-NMR (CDCl3): 0.87 (t, CH3 x 9, J = 6.8 Hz, 27H), 1.20-1.50(m, CH2 x 45, 90H), 1.73 (m, CH2 x 9, 18 H), 3.75 (t, CH2OAr x 2, J = 6.8 Hz, 4H), 3.88 (t, CH2OAr x 4, J = 6.8 Hz, 8H), 3.92 (t, 6H,CH2OAr x 3, J = 6.8 Hz, 6H), 5.02 (s, ArCH2OAr, 4H), 5.05 (s, ArCH2OAr, 2H), 6.59 (s, Ar-H, 2H), 6.62 (s,Ar-H, 4H), 7.41 (s, Ar-H, 2H).

2b12: 50 % yield.1H-NMR (CDCl3): 0.87 (t, CH3 x 9, J = 6.8 Hz, 27H), 1.20-1.50(m, CH2 x 81, 162H), 1.73 (m, CH2 x 9, 18 H), 3.75 (t, CH2OAr x 2, J = 6.8 Hz, 4H), 3.88 (t, CH2OAr x 4, J = 6.8 Hz, 8H), 3.92 (t, 6H,CH2OAr x 3, J = 6.8 Hz, 6H), 5.02 (s, ArCH2OAr, 4H), 5.05 (s, ArCH2OAr, 2H), 6.59 (s, Ar-H, 2H), 6.62 (s,Ar-H, 4H), 7.41 (s, Ar-H, 2H).

References

[1] Iqbal, P.; Mayanditheuar, M.; Childs, L. J.; Hannon, M. J.; Spencer, N.; Ashton, P. R.; Preece, J. A., Materials, 2, 146-168 (2009).

[2] Yang, C.-A.; Wang, G.; Xie, H. L.; Zhang, H. L., Polymer, 31, 4503-4510 (2010).

[3] Percec, V.; Peterca、M.;Tsuda, Y.; Rosen, B. M.; Uchida, S.; Imam, M. R.; Ungar, G.; Heiney, P. A., Chem. Eur. J., 15, 8994-9004 (2009).