To a solution of 2,5-hydroxybenzaldehyde (1.24 g, 8.97 mmol) in dry dichloromethane (20 cm³) were added TBDMSCl (1.35 g , 8.97 mmol) and imidazole. (0.61 g, 8.97 mmol) The mixture was stirred overnight and filtered to remove all insoluble material. All volatiles were removed under reduced pressure and the remaining solid (88% purity by ¹H NMR) recrystallised from hot hexanes. (1.40 g, 62%)

1H NMR (400 MHz, CDCl3): δ no ArOH observed, 9.16 (s, 1H, HC=O), 6.85 (dd, 1H, ³J = 8Hz, ⁴J = 2 Hz, ArH), 6.73 (d, 1H, ⁴J = 2Hz, ArH), 6.68 (d, 1H, ³J = 8Hz ArH).