反应详情

A solution of 2-(4-methylbenzoxazolyl)-5-(hydroxylmethyl)-1,4-bis(hexyloxy)benzene (1.99 g, 4.53 mmol) in CH2Cl2 (10 mL) was added dropwise to a stirred solution of freshly prepared pyridium chlorochromate (PCC) (1.46 g, 6.80 mmol) in CH2Cl2 (100 mL) at room temperature. Anhydrous Et2O (100 mL) was added, and the mixture was stirred for an additional 2 h. The reaction mixture was then directly transferred onto the top of a short silica gel column. The yellow and highly fluorescent product was then washed off the column with CH2Cl2, giving 2,5-bis(hexyloxy)-4-(hydroxymethyl)benzaldehyde in 86.9% (1.72 g). The product (mp. 48-50° C.) had the following spectral properties. 1H NMR (CDCl3, 300 MHz, δ): 10.53 (s, 1H, —CHO), 7.78 (s, 1H), 7.48 (s, 1H), 7.40 (d, J=8.4 Hz, 1H), 7.26 (dd, J=7.8 Hz, J=7.8 Hz, 1H), 7.17 (d, J=7.2 Hz, 1H), 4.18 (t, J=6.6 Hz, 2H), 4.12 (t, J=6.0 Hz, 2H), 2.68 (s, 3H), 1.87 (q, J=6.3 Hz, 4H), 1.54 (m, 4H), 1.35 (m, 8H), 0.90 (m, 6H). IR(KBr): 1684 cm−1, 1609.5 cm−1, 1534.6 cm−1.

1. washThe yellow and highly fluorescent product was then washed off the column with CH2Cl2