Réaction #9241

Équation de réaction

1-(6-bromo-2-benzothiazolyl)-3-ethylurea

3-aminophenyl boric acid

sodium bicarbonate

boric acid

→

desired compound

Rendement 23.4%

1-(6-(3-Aminophenyl)-2-benzothiazolyl)-3-ethylurea

Rendement 23.4%

Solvants

—

mixed solvent

DMF water

MeOH

Conditions de réaction

Traitement

1. 1
   Autrewas purged with nitrogen gas
2. 2
   AutreIt was purged with nitrogen gas again
3. 3
   Concentrationconcentrated
4. 4
   workup.DISSOLUTIONdissolved in methylene chloride
5. 5
   Lavagewashed with sodium bicarbonate solution
6. 6
   Séchagedried (MgSO4)
7. 7
   Autreevaporated
8. 8
   Autrepurified by flash chromatography on SiO2 with MeOH and methylene chloride (1/50)

Mode opératoire

A suspension of 1-(6-bromo-2-benzothiazolyl)-3-ethylurea (0.300 g, 1.00 mmol), 3-aminophenyl boric acid (0.237 g, 1.50 mmol, 1.5 eq), and sodium bicarbonate (0.210 g, 2.50 mmol, 2.5 eq) in 8 mL of mixed solvent DMF/water (5/1) was purged with nitrogen gas. To the mixture, the catalyst Pd(PPh3)4 (0.058 g, 0.05 mmol, 0.05 eq) was added. It was purged with nitrogen gas again, and was heated at about 100° C. in a sealed tube for about 48 hours. More Pd(PPh3)4 (0.025 g, 0.02 mmol, 0.02 eq) and more boric acid (0.080 g, 0.50 mmol, 0.50 eq) were added after the first 24 hours. The mixture was taken up in MeOH, concentrated, dissolved in methylene chloride, washed with sodium bicarbonate solution, dried (MgSO4), evaporated, and purified by flash chromatography on SiO2 with MeOH and methylene chloride (1/50) to give the desired compound 0.073 g (23%). LC/MS 313.2 (M+1); LC retention time 2.11 min.

Source