One‐step reductive etherification of 4‐[18F]fluoro‐benzaldehyde with decaborane

Reductive coupling reactions between 4‐¹⁸F]fluoro‐benzaldehyde (¹⁸F] 1 ) and different alcohols by use of decaborane (B₁₀H₁₄) as reducing agent have the potential to synthesize 4‐¹⁸F]fluoro‐benzylethers in one step. ¹⁸F] 1 was synthesized from 4‐trimethylammonium benzaldehyde (triflate salt) via a standard fluorination procedure (K¹⁸F]F/Kryptofix^® 222) in dimethylformamide at 90°C for 25 min and purified by solid‐phase extraction. Subsequently, reductive etherifications of ¹⁸F] 1 were performed as one‐step reactions with primary and secondary alcohols, mediated by B₁₀H₁₄ in acetonitrile at 60°C. Various 4‐¹⁸F]fluorobenzyl ethers (6 examples are shown) were obtained within 1–2 h reaction time in decay‐corrected radiochemical yields of 12–45%. Copyright © 2006 John Wiley & Sons, Ltd.