Methanol → Methyl 3-bromocinnamate, predominantly trans

HRID 1635675Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4](/[CH:8]=[CH:9]/[C:10]([OH:12])=[O:11])[CH:5]=[CH:6][CH:7]=1.S(=O)(=O)(O)O.[CH3:18]O>>[Br:1][C:2]1[CH:3]=[C:4](/[CH:8]=[CH:9]/[C:10]([O:12][CH3:18])=[O:11])[CH:5]=[CH:6][CH:7]=1

Participants

Reactant 3

HCID 887Methanol

HCID 1118Sulfuric Acid

HCID 776461m-Bromocinnamic acid

Product 1

HCID 1482751Methyl 3-bromocinnamate, predominantly transYield 47%

Procedure

A solution of trans-3-(3-bromophenyl)-2-propenoic acid (0.405 mol) in methanol (300 ml) was treated with conc. sulfuric acid (6.0 ml) and heated under reflux for 10 h. The cooled mixture was filtered to afford the title compound (46.14 g, 47%) as brilliant white crystals, m.p. 53-55° C. (Found: C, 50.10; H, 3.58; Br; 33.21. C10H9BrO2 requires C, 49.82; H, 3.76; Br, 33.14%); νmax (nujol)/cm−1 1730.5, 1715.0, 1644; δH (270 MHz) 3.81 (3H, s, OCH3); 6.43 (1H, d, 2-H, 3J2,3=16.2 Hz); 7.25 (1H, t, 5′-H, Jo=7.8 Hz); 7.43 (1H, dt, 4′-H, Jo=7.9, Jm=1.0 Hz); 7.50 (1H, dt, 6′-H, Jo=7.9, Jm=1.0 Hz); 7.60 (1H, d, 3-H, 3J3,2=16.2 Hz); 7.66 (1H, t, 2′-H, Jm=1.7 Hz). δc (67.8 MHz) 51.8 (OCH3); 123.0 (3′-C); 133.0 (4′-C); 136.4 (1′-C); 143.1 (3-C); 166.9 (CO2Me). Remaining signals lie in the range 119.3-130.7 ppm; m/z 242.0, 240.0 (46.67, 47.64, M+), 211.0, 209.0 (72.69, 74.00), 182.9, 180.9 (15.67, 16.83), 161.0 (4.19), 130.0 (9.44), 102.1 (100).

Workup

temperatureheated
temperatureunder reflux for 10 h
filtrationThe cooled mixture was filtered

Sources & evidence

ORD record: ord-350f5df4ad3e4790b7ca1d584c95cbb0
Source dataset: uspto-grants-2003_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06509476B1

Reaction notes

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