Acetic Anhydride → (2R,3R,4S)-6-acetylamino-3,4-dihydro-3-hydroxy-2-dimethoxymethyl-2-methyl-4-(2-thioxobenzoxazol-3-yl)-2H-1-benzopyran

HRID 29034Notes

Reaction equation

HRID 29034 reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][C@:9]([CH:12]([O:15][CH3:16])[O:13][CH3:14])([CH3:11])[C@H:8]([OH:17])[C@@H:7]([N:18]3[C:22]4[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=4[O:20][C:19]3=[S:27])[C:6]=2[CH:28]=1.[C:29](OC(=O)C)(=[O:31])[CH3:30].C(N(CC)CC)C.C([O-])(O)=O.[Na+]>ClCCl.CN(C)C1C=CN=CC=1>[C:29]([NH:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][C@:9]([CH:12]([O:15][CH3:16])[O:13][CH3:14])([CH3:11])[C@H:8]([OH:17])[C@@H:7]([N:18]3[C:22]4[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=4[O:20][C:19]3=[S:27])[C:6]=2[CH:28]=1)(=[O:31])[CH3:30]

Participants

7

Reactant 4

HCID 7918Acetic AnhydrideHCID 8471TriethylamineHCID 516892Sodium BicarbonateHCID 86612091(2R,3R,4S)-6-amino-3,4-dihydro-3-hydroxy-2-dimethoxymethyl-2-methyl-4-(2-thioxobenzoxazol-3-yl)-2H-1-benzopyran

Product 1

HCID 86612094(2R,3R,4S)-6-acetylamino-3,4-dihydro-3-hydroxy-2-dimethoxymethyl-2-methyl-4-(2-thioxobenzoxazol-3-yl)-2H-1-benzopyranYield 86.4%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

100 mg (0.25 mmol) of the compound obtained in Example 17 was dissolved in 2 ml of dichloromethane, to which 23 μl (0.25 mmol) of acetic anhydride, 52 μl (0.37 mmol) of triethylamine and 9.1 mg (0.07 mmol) of 4-dimethylaminopyridine were added in that order. The reaction was stirred for 3 hours at room temperature, 10 ml of saturated NaHCO3 solution was added and extraction was performed with 40 ml of dichloromethane. The extract was washed with brine and dried over anhydrous MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=2:1), to give 96 mg (yield: 86%) of the target compound.

Workup

  1. additionwere added in that order
  2. extractionextraction
  3. washThe extract was washed with brine
  4. dry with materialdried over anhydrous MgSO4
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=2:1)

Sources & evidence

ORD record
ord-eaa353b2ce354d8380e4c83e5a0608be
Source dataset
uspto-grants-2008_09
Patent number
US07420060B2

Reaction notes

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