4-(4-Nitrophenyl)morpholin-3-one and 4-(4-aminophenyl) morpholin-3-one are the key intermediates for rivaroxaban synthesis. A facile and economically efficient process has been developed for the preparation of these intermediates. Excellent yield of 4-(4-nitrophenyl)morpholine is obtained by condensing 4-chloro nitrobenzene and morpholine, and 4-(4-nitrophenyl)morpholine is oxidized using inexpensive sodium chlorite to achieve a good yield of the corresponding 4-(4-nitrophenyl)morpholin-3-one. Finally, the key intermediate of rivaroxaban, 4-(4-aminophenyl) morpholin-3-one, is achieved by the iron(III)-catalyzed reduction of the nitro group with aqueous hydrazine. No high-cost materials were used, and the process did not require column purification.

中文翻译：

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以亚氯酸钠为唯一氧化剂，通过酸催化选择性氧化4-（4-硝基苯基）吗啉制备4-（4-硝基苯基）吗啉-3-酮

4-（4-硝基苯基）吗啉-3-酮和4-（4-氨基苯基）吗啉-3-酮是利伐沙班合成的关键中间体。已经开发了用于制备这些中间体的简便且经济有效的方法。通过缩合4-氯硝基苯和吗啉可得到4-（4-硝基苯基）吗啉的极佳收率，并且使用廉价的亚氯酸钠氧化4-（4-硝基苯基）吗啉可得到相应的4-（4-硝基苯基）吗啉-3-一。最后，利伐沙班的关键中间体4-（4-氨基苯基）吗啉-3-酮是通过铁（III）用肼水溶液还原硝基而得到的。没有使用高成本的材料，并且该过程不需要柱纯化。