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

HRID 2050977Notes

Reaction equation

HRID 2050977 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-7754b97777ac449f8d92eed6e73985cf
Source dataset
uspto-grants-1991_05
Patent number
US05015661

Reaction notes

Loading…