The present invention provides an improved process for preparation of the substantially pure trazodone and its hydrochloride salt. The process comprises reaction of the compound- Π (as described) with the compound-Ill (as described) optionally in the presence of an inorganic base, and a catalyst; wherein in the said process the trazodone free base and/or its hydrochloride salt are isolated by precipitation at lower temperature. The improved process for the preparation of trazodone hydrochloride (the compound I) provides the product with total amount of alkylating substances (as described herein) as impurity in less than 10 ppm. The improved process for the preparation of trazodone hydrochloride (the compound I) provides the product with total amount of l-(3-chlorophenyl)-4-(3-chloropropyl) piperazine as an impurity in less than 2.5 ppm.
本发明提供了一种改进的制备几乎纯
曲唑酮及其盐酸盐的过程。该过程包括将化合物-Π(如所述)与化合物-III(如所述)在
无机碱和催化剂的存在下反应;在该过程中,
曲唑酮游离碱和/或其盐酸盐通过在较低温度下沉淀而得到。制备
曲唑酮盐酸盐(化合物I)的改进过程将烷基化物(如本文所述)的总量作为杂质控制在不到10ppm。制备
曲唑酮盐酸盐(化合物I)的改进过程将1-(3-
氯苯基)-4-(3-
氯丙基)
哌嗪的总量作为杂质控制在不到2.5ppm。