Acetic Acid → 4-(Bromomethyl)benzaldehyde

Participants

Reaction Steps

Alcohol 2 (6.46 g, 47.5) was dissolved in DCM (100 ml) before HBr in acetic acid (33 wt %, 42 ml, 243, 5 eq) was added and stirred overnight. Water (100 ml) was added to the reaction mixture and the phases were separated and the organic phase obtained was washed with a NaOH solution (2 M, 2×100 ml), dried over Na2SO4, and evaporated. The residue was washed through a silica plug to yield 3 as a white solid (9.04 g, 45.4 mmol, 95%). Rf=0.77 (DCM); m.p.=100° C. (recrystallised from hexane); νmax=1682, 1604, 1209, 1200, 830, 770, 726 cm−1; 1H NMR (300 MHz, CDCl3) δ=10.02 (s, 1H, CHO), 7.87 (d, 3J(H,H)=8.2 Hz, 2H, ArCH α to CHO), 7.56 (d, 3J(H,H)=8.2 Hz, 2H, ArCH α to CH2Br), 4.52 (s, 21-1, CH2Br); 13C NMR (75 MHz, CDCl3) δ=191.5 (CHO), 144.2 (ArCCBr), 136.2 (ArCCHO), 130.2 (ArCH α to ArCCHO), 129.7 (ArCH α to ArCCH2Br), 31.9 (CH2Br); HRMS (ESI−): m/z calculated for C8H6BrO [M−H]−: 196.9602, found 196.9602; elemental analysis calcd (%) for C8H7BrO (199.04): C, 48.27; H, 3.54. found: C, 47.40; H, 3.53.

Provenance & Evidence