Reaktion #999609

Reaktionsgleichung

3,4-dihydro-2H-benzo[b][1,4]oxazine-8-carboxylic acid

4-tert-butylbenzen-1,2-diamine

diisopropylethylamine

O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate

→

title compound

Ausbeute 98.0%

4-(5-tert-butyl-1H-benzo[d]imidazol-2-yl)benzene amine

Ausbeute 98.0%

Lösungsmittel

ethylacetate

acetic acid toluene

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with a saturated sodium bicarbonate solution
2. 2
   Trocknena saturated NaCl solution, and dried over magnesium sulfate
3. 3
   Einengenbefore being concentrated in a vacuum
4. 4
   SonstigeThe residue thus obtained
5. 5
   workup.STIRRINGstirred at 70° C. for 4 hrs
6. 6
   Temperaturcooled to room temperature
7. 7
   Einengenconcentrated in a vacuum
8. 8
   workup.DISSOLUTIONThe concentrate was dissolved in ethylacetate
9. 9
   Waschenwashed with a saturated sodium bicarbonate solution
10. 10
    Trocknena saturated NaCl solution, and dried over magnesium sulfate before vacuum concentration
11. 11
    SonstigePurification by column chromatography (developing solvent: ethylacetate/hexane=1/1)

Vorschrift

To a solution of 3,4-dihydro-2H-benzo[b][1,4]oxazine-8-carboxylic acid 3.6 g (20 mmol) of step 4 in dimethylformamide 50 mL were added 4-tert-butylbenzen-1,2-diamine 3.3 g (20 mmol), diisopropylethylamine 7 mL (40 mmol) and O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate 11 g (30 mmol), followed by stirring at room temperature for 3 hrs. The reaction mixture was diluted with ethylacetate, washed with a saturated sodium bicarbonate solution and a saturated NaCl solution, and dried over magnesium sulfate before being concentrated in a vacuum. The residue thus obtained was dissolved in acetic acid/toluene (45 mL/5 mL), stirred at 70° C. for 4 hrs, cooled to room temperature, and concentrated in a vacuum. The concentrate was dissolved in ethylacetate, washed with a saturated sodium bicarbonate solution and a saturated NaCl solution, and dried over magnesium sulfate before vacuum concentration. Purification by column chromatography (developing solvent: ethylacetate/hexane=1/1) gave 5.2 g of the title compound (yield 85%).

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