Acetic Anhydride → 2-(1-Benzyl-2-oxo-2,3-dihydro-1h-indol-3-yl)-n,n-dimethyl-acetamide

HRID 71043Notes

Reaction equation

HRID 71043 reaction equation
[CH2:1]([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:10]([CH2:18][C:19]([N:21]([CH3:23])[CH3:22])=[O:20])(O)[C:9]1=[O:24])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(OC(=O)C)(=O)C>[Zn].C(O)(=O)C>[CH2:1]([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[CH:10]([CH2:18][C:19]([N:21]([CH3:23])[CH3:22])=[O:20])[C:9]1=[O:24])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 104039792-(1-Benzyl-3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)-N,N-dimethyl-acetamide

Product 1

HCID 104479902-(1-Benzyl-2-oxo-2,3-dihydro-1h-indol-3-yl)-n,n-dimethyl-acetamide

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent

Procedure

A flask is charged with 2-(1-benzyl-3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)-N,N-dimethyl-acetamide (Example 19) (10.0 g, 30.8 mmol), acetic acid (250 mL), acetic anhydride (100 g), and Zn-dust (20 g). The mixture is kept under reflux, until all of the starting material is consumed (3 h). The solids are then filtered off, and from the filtrate the solvent is removed to leave an oil which crystallizes to a pale brown solid on treatment with di-iso-propyl ether. Yield of the title compound: 9.2 g (96.8%). 1H-NMR (CDCl3, 300 MHz) δ 2.73 (dd, 1, 2J=16.5 Hz, J=9.4 Hz, CH2NMe2); 3.00, 3.01 (2 s, 6, N(CH3)2); 3.20 (dd, 1, J=3.2 Hz, CH2NMe2); 4.06 (dd, 1, H-3); 4.90, 4.97 (AB, 2, 2J=15.6 Hz, CH2N); 6.70 (d, 1, J=7.9 Hz, H-7); 6.97 (“dtr”, J=7.5 Hz, J=1.2 Hz, H-5); 7.13 (“dtr”, J=7.8 Hz, J=1.2 Hz, H-6); 7.22-7.29, 7.29-7.33 (m, 5, 5 Ph-H); 7.38 (br d, 1, J=7.5 Hz, H-4). 13C-NMR (CDCl3, 75 MHz) δ 35.25 (CH2NMe2); 36.07, 37.51 (N(CH3)2); 42.59 (C-3); 44.28 (NCH2Ph); 109.12 (C-7); 122.66 (C-5); 124.85 (C-4); 127.49 (Ph meta-C); 127.71 (Ph para-C); 128.04 (C-6); 128.92 (Ph ortho-C); 129.63 (C-9); 136.19 (Ph ipso-C); 143.52 (C-8); 170.00 (CONMe2); 178.02 (C-2),

Workup

  1. temperatureunder reflux
  2. customuntil all of the starting material is consumed (3 h)
  3. filtrationThe solids are then filtered off
  4. customfrom the filtrate the solvent is removed
  5. customto leave an oil which
  6. customcrystallizes to a pale brown solid on treatment with di-iso-propyl ether

Sources & evidence

ORD record
ord-3fc913ea47ec40f5b9fac9446238ce50
Source dataset
uspto-grants-2014_09
Patent number
US08822702B2

Reaction notes

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