Sulfuric Acid → 2-(Thiophen-2-ylmethyl)isoindoline-1,3-dione

HRID 2113732Notes

Reaction equation

HRID 2113732 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH2:6][NH:7][C:8](=[O:18])[C:9]1[C:10](=[CH:14][CH:15]=[CH:16][CH:17]=1)[C:11]([OH:13])=O.OS(O)(=O)=O>CO>[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH2:6][N:7]1[C:8](=[O:18])[C:9]2[C:10](=[CH:14][CH:15]=[CH:16][CH:17]=2)[C:11]1=[O:13]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 178101612-[[(2-Thienylmethyl)amino]carbonyl]benzoic acid

Product 1

HCID 33541542-(Thiophen-2-ylmethyl)isoindoline-1,3-dioneYield 70%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 2-aminomethyl-thiophene (2.1 ml, 20.5 mmol) in CHCl3 (25 ml) is treated with phthalic anhydride (3.0 g, 20.5 mmol) at r.t. for 5 min, then at reflux for 20 min, whereupon a white powder precipitated out. This powder is collected by filtration and dried in vacuo to give N-thiophen-2-ylmethyl-phthalamic acid (4.42 g, 83%) as white crystals. An aliquot of this phthalamic acid (2.13 g, 8.12 mmol) is dissolved in MeOH (12 ml), treated with H2SO4 (440 μl, 8.25 mmol) and heated to reflux for 1.5 h, whereupon a white powder precipitated out. This powder is collected by filtration and dried in vacuo to give 1.38 g (70%) of the title phthalimide as white crystals: 1H NMR (DMSO-d6) δ7.92-7.82 (m., 4H), 7.42 (dd, J=5.1, 1.2 Hz, 1H), 7.08 (dd, J=4.0, 0.8 Hz, 1H), 6.95 (dd, J=5.1, 3.5 Hz, 1H), 4.92 (s, 2H).

Workup

  1. temperatureheated
  2. temperatureto reflux for 1.5 h, whereupon a white powder
  3. customprecipitated out
  4. filtrationThis powder is collected by filtration
  5. customdried in vacuo

Sources & evidence

ORD record
ord-9c3c9a1407834b048a3980fa3ea33418
Source dataset
uspto-grants-2008_10
Patent number
US07432286B1

Reaction notes

Loading…