Synthesis of Branched Benzaldehyde Derivative

5-Chloro-4-((3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-methylbenzyl)oxy)-2-hydroxybenzaldehyde
(2c) (100 mg, 243 μmol, 1.0 equiv) was mixed with
Cs₂CO₃ (159 mg, 487 μmol, 2.0 equiv) under
N₂ atmosphere in a round-bottom flask. 3-(Bromomethyl)benzonitrile
(95.4 mg, 487 μmol, 2.0 equiv) and cat. KI (0.8 mg, 4.8 μmol,
0.02 equiv) were dissolved in 0.5 mL of dry DMF, added to the flask,
and continuously stirred at room temperature for 1 day. The product
was purified by silica gel chromatography using a 1:1 hexane/EtOAc
mixture. Organic solvents were removed in vacuo yielding
a colorless solid (104 mg, 81% yield).
Purity: 96.27% as determined
by HPLC setup 1, UV detector: 254 nm.
¹H NMR (400
MHz, CDCl₃): δ 10.32 (s,
1H), 7.91 (s, 1H), 7.72 (s, 1H), 7.68 (d, J = 8.0
Hz, 2H), 7.54 (t, J = 7.8 Hz, 1H), 7.39 (m, 1H),
7.26–7.25 (m, 2H), 6.92 (d, J = 8.2 Hz, 1H),
6.81 (d, J = 2.0 Hz, 1H), 6.77 (dd, J = 8.2 Hz, J = 2.0 Hz, 1H), 6.60 (s, 1H), 5.20 (s,
2H), 5.18 (s, 2H), 4.31 (s, 4H), 2.28 (s, 3H).
ESI-MS ([M +
Na]⁺): m/z calculated
([C₃₁H₂₄ClNO₅ + Na]⁺)
= 548.1235. Found = 548.1223.