Reaction #657252

ord-bf5005f846794a4ab660f2c1eb1fa35e

Reaction equation

O=Cc1cc(Br)cc2c1OCC2
20
O=Cc1cc(Br)cc2c1OCC2
5-Bromo-2,3-dihydrobenzofuran-7-carbaldehyde
CN[C@@H](C)[C@@H](O)c1ccccc1
(1S,2S) pseudoephedrine
→
C[C@H]1[C@H](c2ccccc2)OC(c2cc(Br)cc3c2OCC3)N1C
21
Yield 79.0%
C[C@H]1[C@H](c2ccccc2)OC(c2cc(Br)cc3c2OCC3)N1C
(4S,5S)-2-(5-bromo-2,3-dihydrobenzofuran-7-yl)-3,4-dimethyl-5-phenyl-1,3-oxazolidine
Yield 79.0%

Reactants

O=Cc1cc(Br)cc2c1OCC2
20
O=Cc1cc(Br)cc2c1OCC2
5-Bromo-2,3-dihydrobenzofuran-7-carbaldehyde
CN[C@@H](C)[C@@H](O)c1ccccc1
(1S,2S) pseudoephedrine

Reagents

None

Solvents

c1ccccc1
benzene

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    OtherSolvent removal
  2. 2
    Otheryielded yellow crystals which
  3. 3
    Otherwere recrystallized from a minimum of hot hexanes

Procedure

A sample of 20 (650 mg, 2.9 mmol) and (1S,2S) pseudoephedrine (500 mg, 3.0 mmol) in 40 mL of benzene was refluxed overnight using a Dean-Stark trap. Solvent removal yielded yellow crystals which were recrystallized from a minimum of hot hexanes to give white crystals of 21 (841 mg, 79%), mp=83.5-85.5° C.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US09023317B2uspto-grants-2015_05