Method for the production of 4-(4-aminophenyl)-3-morpholinone

1. A process for preparing 4-(4-aminophenyl)-3-morpholinone comprising reacting 4-(4-nitrophenyl)-3 -morpholinone with hydrogen in the presence of a hydrogenation catalyst, the reaction being effected in an aliphatic alcohol.

2. The process for preparing 4-(4-aminophenyl)-3-morpholinone according to claim 1 , wherein the aliphatic alcohol is ethanol.

3. The process for preparing 4-(4-aminophenyl)-3-morpholinone according to claim 1 or 2 , characterized in that said 4-(4-nitrophenyl)-3-morpholinone is prepared by nitrating 4-phenyl-3-morpholinone.

4. The process according to claim 3 , wherein the 4-(4-nitrophenyl)-3-morpholinone prepared by nitration is worked up by extraction with acetone.

5. The process according to claim 4 , wherein the 4-(4-nitrophenyl)-3-morpholinone is isolated by crystallization from an acetone/water mixture after the extraction.

6. The process according to claim 3 , wherein 4-phenyl-3-morpholinone is prepared by reacting 2-anilinoethanol with chloroacetyl chloride.

7. The process according to claim 6 , wherein chloroacetyl chloride and base are metered in simultaneously.

8. The process according to claim 7 , wherein the base is aqueous sodium hydroxide solution.

9. The process according to claim 8 , wherein chloroacetyl chloride and sodium hydroxide solution are added at an internal temperature of 35 to 45°C. and while maintaining a pH of the reaction solution between 12 and 12.5.

10. A process for preparing 5-chloro-N-({(5S)-2-oxo-3-[4-(3-oxo-4-morpholinyl)phenyl]-1,3-oxazolidin-5-yl}methyl)-2-thiophenecarboxamide, comprising first reacting 4-(4-aminophenyl)-3-morpholinone prepared according to claim 1 with 2-[(2S)-2-oxiranylmethyl]-1H-isoindole-1,3 (2H)-dione and subsequently reacting the initial reaction product with 5-chlorothiophene-2-carbonyl chloride.