Acetic Anhydride → rac-6-Acetyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2-(phenyl-ethynyl)-2H-1-benzopyran

HRID 654514Notes

Reaction equation

HRID 654514 reaction equation
[CH3:1][C:2]1([C:16]#[C:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[CH2:7][CH2:6][C:5]2[C:8]([CH3:15])=[C:9]([OH:14])[C:10]([CH3:13])=[C:11]([CH3:12])[C:4]=2[O:3]1.[C:24](OC(=O)C)(=[O:26])[CH3:25]>N1C=CC=CC=1>[C:24]([O:14][C:9]1[C:10]([CH3:13])=[C:11]([CH3:12])[C:4]2[O:3][C:2]([CH3:1])([C:16]#[C:17][C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=3)[CH2:7][CH2:6][C:5]=2[C:8]=1[CH3:15])(=[O:26])[CH3:25]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 151718093,4-dihydro-2,5,7,8-tetramethyl-2-(2-phenylethynyl)-2H-1-benzopyran-6-ol

Product 1

HCID 15171916rac-6-Acetyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2-(phenyl-ethynyl)-2H-1-benzopyran

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A mixture of 0.3 g of rac-3,4-dihydro-2,5,7,8-tetramethyl-2-(phenylethynyl)-2H-1-benzopyran-6-ol, 7 ml of pyridine and 0.5 ml of acetic anhydride was allowed to sit at room temperature over night. The reagents were evaporated under reduced pressure, at the end azeotropically with toluene. The residue was crystallized from hexane to give 0.21 g of colorless crystals with m.p. 123°-125°.

Workup

  1. waitto sit at room temperature over night
  2. customThe reagents were evaporated under reduced pressure, at the end azeotropically with toluene
  3. customThe residue was crystallized from hexane

Sources & evidence

ORD record
ord-12b61da4b3964af28daa966ef1cf5935
Source dataset
uspto-grants-1992_07
Patent number
US05132310

Reaction notes

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