Methanol → Methyl 3-bromocinnamate, predominantly trans

HRID 1275385Notes

Reaction equation

HRID 1275385 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

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 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%); Vmax (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, 1683), 161.0 (4.19), 130.0 (9.44), 102.1 (100).

Workup

  1. temperatureheated
  2. temperatureunder reflux for 10 h
  3. filtrationThe cooled mixture was filtered

Sources & evidence

ORD record
ord-890ad4cd0cb544839db6de314e4c7f61
Source dataset
uspto-grants-2000_12
Patent number
US06160120

Reaction notes

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