N,N'-Dimethylethylenediamine → 4,4'-Diaminobenzil

HRID 525636Notes

Reaction equation

HRID 525636 reaction equation
P([O-])([O-])([O-])=O.[K+].[K+].[K+].C(=O)(OC(C)(C)C)[NH2:10].Br[C:18]1[CH:23]=[CH:22][C:21]([C:24]([C:26]([C:28]2[CH:33]=CC(Br)=[CH:30][CH:29]=2)=[O:27])=[O:25])=[CH:20][CH:19]=1.CN[CH2:37][CH2:38][NH:39]C>[Cu]I.C1COCC1>[NH2:10][C:18]1[CH:23]=[CH:22][C:21]([C:24]([C:26]([C:28]2[CH:33]=[CH:37][C:38]([NH2:39])=[CH:30][CH:29]=2)=[O:27])=[O:25])=[CH:20][CH:19]=1

Participants

7

Reactant 4

HCID 8070N,N'-DimethylethylenediamineHCID 62657Potassium Phosphate, TribasicHCID 77922tert-Butyl carbamateHCID 964304,4'-Dibromobenzil

Product 1

HCID 2751374,4'-Diaminobenzil

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
90 °C

Procedure

A Schlenk flask was thoroughly flame-dried under vacuum and then under nitrogen atmosphere (three cycles each). To this was added copper (I) iodide (4.14 g, 22 mmol), tribasic potassium phosphate (46.2 g, 220 mmol), and t-butyl carbamate (13.92 g, 119 mmol). These reagents were dried under vacuum and back-filled with nitrogen (three cycles). To this was added 4,4′-dibromobenzil, 1 (20 g, 54 mmol), N,N′-dimethylethylenediamine (3.82 g (4.7 mL), 43 mmol) and anhydrous THF (100 mL). The reaction flask was sealed under nitrogen and heated at 90° C. for 24 h. After bringing down to room temperature, the reaction mixture was passed through silica gel to remove the copper salts. The product was extracted with ethyl acetate and purified by column chromatography using 1:4 mixtures of ethyl acetate and hexane as eluant to obtain yellow crystalline solid. Yield: 17.5 g (73%). Mp. 207° C. 1H NMR (acetone-d6, 400 MHz): 1.50 (s, 18H), 7.78 (m, 4H), 7.89 (m, 4H), 8.98 (bs, 2H). 13C NMR (acetone-d6, 100 MHz): 194.5, 153.2, 146.9, 131.3, 128.0, 118.5, 81.1, 28.4. FT-IR (cm−1): ν 3332, 2925, 1682, 1598, 1509, 1455, 1414, 1368, 1313, 1221, 1169, 1144, 1050, 996, 914, 885, 830, 771. HRMS-FAB: mlz M+ calcd 440.1947. found 440.1938.

Workup

  1. customA Schlenk flask was thoroughly flame-dried under vacuum
  2. customThese reagents were dried under vacuum
  3. additionback-filled with nitrogen (three cycles)
  4. customThe reaction flask was sealed under nitrogen
  5. customAfter bringing down to room temperature
  6. customto remove the copper salts
  7. extractionThe product was extracted with ethyl acetate
  8. custompurified by column chromatography
  9. customto obtain yellow crystalline solid

Sources & evidence

ORD record
ord-b394aab82d984e79a8b206648bf8d316
Source dataset
uspto-grants-2016_05
Patent number
US09340635B2

Reaction notes

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