Acetic Anhydride → N-(2,3-dihydro-1,4-benzodioxin-5-yl)acetamide

HRID 1487200Notes

Reaction equation

HRID 1487200 reaction equation
[O:1]1[CH2:6][CH2:5][O:4][C:3]2[C:7]([NH2:11])=[CH:8][CH:9]=[CH:10][C:2]1=2.[C:12](OC(=O)C)(=[O:14])[CH3:13]>C(O)C>[O:1]1[CH2:6][CH2:5][O:4][C:3]2[C:7]([NH:11][C:12](=[O:14])[CH3:13])=[CH:8][CH:9]=[CH:10][C:2]1=2

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 117883872,3-Dihydro-1,4-benzodioxin-5-amine2×

Product 1

HCID 658593N-(2,3-dihydro-1,4-benzodioxin-5-yl)acetamideYield 95%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 2,3-dihydrobenzo[b][1,4]dioxin-5-amine (Intermediate B3, 4.5 g, 30 mmol) in ethanol (50 mL) at room temperature was slowly added acetic anhydride (3.0 g, 30 mmol). After the addition was over, the mixture was stirred at room temperature for 5 minutes. The resulting suspension was concentrated to give the crude product, which was purified by silica gel column chromatography (petroleum ether/ethyl acetate 4/1) to afford the product N-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acetamide (5.5 g, yield 95%). 1H NMR (400 MHz, CDCl3) δ ppm 9.12 (s, 1H), 7.44-7.46 (d, 1H, J=8.0 Hz), 6.71-6.75 (t, 1H, J=8.0 Hz), 6.59-6.61 (d, 1H, J=7.6 Hz), 4.23-4.30 (m, 4H), 2.06 (s, 3H).

Workup

  1. customat room temperature
  2. additionAfter the addition
  3. concentrationThe resulting suspension was concentrated
  4. customto give the crude product, which
  5. customwas purified by silica gel column chromatography (petroleum ether/ethyl acetate 4/1)

Sources & evidence

ORD record
ord-aad21df284a645318e6f503c791ea2df
Source dataset
uspto-grants-2016_08
Patent number
US09428508B2

Reaction notes

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