Reaktion #72781

Reaktionsgleichung

methyl 3-amino-5-(4-morpholinyl)-2-nitrobenzoate

DCM

HOAc

→

desired product

Ausbeute 77.0%

methyl 2-methyl-5-(4-morpholinyl)-1H-benzimidazole-7-carboxylate

Ausbeute 77.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Temperaturat reflux for 5 h
3. 3
   Sonstigethe solvent was removed in-vacuo
4. 4
   ExtraktionIt was extracted with EtOAc (500 mL×3)
5. 5
   EinengenThe combined organic layers were then concentrated in-vacuo
6. 6
   Sonstigethe residue was purified by silica gel chromatography
7. 7
   Wascheneluted with MeOH

Vorschrift

To a solution of methyl 3-amino-5-(4-morpholinyl)-2-nitrobenzoate (22 g) stirring at reflux in HOAc (400 mL) was added iron powder in portions (13 g). After the addition, the mixture was stirred at reflux for 5 h. It was cooled to room temperature and the solvent was removed in-vacuo. The residue was neutralized with aqueous Na2CO3 solution (1 L). It was extracted with EtOAc (500 mL×3). The combined organic layers were then concentrated in-vacuo and the residue was purified by silica gel chromatography eluted with MeOH:DCM=1:30 to afford the desired product as a solid (16.6 g, yield 77%). 1H NMR (300 MHz, CDCl3): δ ppm 2.67 (s, 3H), 3.17 (t, 4H, J=4.8 Hz), 3.90 (t, 4H, J=4.8 Hz), 3.98 (s, 3H), 7.44 (d, 1H, J=1.8 Hz), 7.54 (d, 1H, J=1.8 Hz); LC-MS: m/e=276 [M+1]+.

Quelle