Triethylamine → dimethyl 6-nitro-2-oxo-1H-indole-3,3-dicarboxylate

HRID 1603036Notes

Reaction equation

HRID 1603036 reaction equation
C([N:3]([CH2:6]C)CC)C.C([C:11]1[CH:16]=[C:15]([N+:17]([O-:19])=[O:18])[CH:14]=[CH:13][C:12]=1[CH:20]([C:25]([O:27][CH3:28])=[O:26])[C:21]([O:23][CH3:24])=[O:22])(O)=O.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:36])C=CC=CC=1>>[CH3:28][O:27][C:25]([C:20]1([C:21]([O:23][CH3:24])=[O:22])[C:12]2[C:11](=[CH:16][C:15]([N+:17]([O-:19])=[O:18])=[CH:14][CH:13]=2)[NH:3][C:6]1=[O:36])=[O:26]

Participants

4

Reactant 3

HCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 108039332-(1,3-Dimethoxy-1,3-dioxopropan-2-yl)-5-nitrobenzoic acid

Product 1

HCID 10732518dimethyl 6-nitro-2-oxo-1H-indole-3,3-dicarboxylateYield 84.4%

Procedure

Triethylamine (8.64 mL, 62 mmol) was added to a solution of dimethyl (2-carboxy-4-nitrophenyl)malonate (18.43 g, 62 mmol) and diphenylphosphoryl azide (DPPA, 13.4 mL, 62 mmol) and the mixture stirred at reflux for 15 h. The orange-brown solution was cooled, concentrated to a small volume, and the solid filtered off, washing with 2N HCl then water. The solid was triturated with hot MeOH (ca. 80 mL) to give title compound as a pale yellow powder (15.4 g, 84%), mp 234-239° C. (dec.). 1H NMR ((CD3)2SO) δ11.43 (br s, 1H, NH), 7.97 (dd, J=8.3, 2.1 Hz, 1H, H-5), 7.66 (d, J=8.3 Hz, 1H, H-4), 7.62 (d, J=2.1 Hz, 1H, H-7), 3.76 (s, 6H, CO2Me); 13C NMR δ167.4, 163.9 (CO2Me, CONH), 148.4, 143.7, 130.4 (C-6,8,9), 126.7, 117.7, 104.6 (C-4,5,7), 65.7 (C-3), 54.0 (OMe); IR (KBr) 1767 (CONH), 1736 (CO2Me), 1524 (NO2), 1348 (NO2), 1246 cm-1; MS (DEI) 294 (85%, M+), 250 (100%, M--CO2); HRMS calcd. for C12H10N2O7 294.04880, found 294.04851. Anal. Calculated for C12H10N2O: C, 49.0; H, 3.4; N, 9.5. Found: C, 49.1; H, 3.4; N, 9.6%.

Workup

  1. temperatureat reflux for 15 h
  2. temperatureThe orange-brown solution was cooled
  3. concentrationconcentrated to a small volume
  4. filtrationthe solid filtered off
  5. washwashing with 2N HCl
  6. customThe solid was triturated with hot MeOH (ca. 80 mL)

Sources & evidence

ORD record
ord-a020a0dc6eca4a59b369b08cd42214ba
Source dataset
uspto-grants-1999_11
Patent number
US05985909

Reaction notes

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