Synthesis and antiemetic activity of 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4 H -carbazol-4-one derivatives
ABSTRACT 5-HT3 receptor antagonists, such as Ondansetron, are used for anti-emesis after chemotherapy, radiotherapy and operations. Some
Ondansetron analogs possessing piperazine ring as side chains were synthesized in our lab. Thus, one of the two carbonyl groups
of starting material 1,3-cyclohexandione (1) was condensed with phenylhydrazine hydrochloride to form monophenylhydrazone (2). 1,2,3,9-Tetrahydro-4H-carbazol-4-one (3) was prepared from 2
via cyclization and rearranged in the presence of ZnCl2. Through a methylation reaction, compound 3 was converted to 1,2,3,9-tetrahydro-9-methyl-4H-carbazol-4-one (4). 3-Dimethylaminomethyl substituted compound (5) was synthesized from 4 by a Mannich reaction in glacial acetic acid. Nine novel 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives (6a–6i) were synthesized through nucleophilic substitution reaction of 5 with piperazines. The structures of all the target compounds were determined by elemental analysis, IR, MS, 1H NMR and 13C NMR spectra. The results of preliminary pharmacological test show that part of the novel compounds have antiemetic activity
comparable to that of the control Ondansetron.
- Seminars in Anesthesia Perioperative Medicine and Pain - SEMIN ANESTH PERIOPERAT MED P. 01/1996; 15(1):41-46.
Article: Ondansetron[Show abstract] [Hide abstract]
ABSTRACT: Ondansetron is the first selective antagonist of the 5-hydroxytryptamine receptors (type 3) marketed for the prevention of emesis induced by antineoplastic agents. Ondansetron has been shown to be more active and less toxic than high-dose metoclopramide in patients submitted to cisplatin chemotherapy. Furthermore, when dexamethasone was added to ondansetron, its antiemetic efficacy increased significantly. In the prevention of emesis induced by a high single dose of cisplatin or by repeated low doses, ondansetron combined with dexamethasone has been shown to be the more efficacious and less toxic antiemetic treatment. However, in the prevention of delayed emesis from cisplatin, its role is still to be defined. In patients submitted to moderately emetogenic chemotherapeutic agents, ondansetron has shown an efficacy superior or equal to standard doses of metoclopramide, but is less toxic. Moreover, when compared with dexamethasone, its antiemetic efficacy and tolerability is similar; in this group of patients ondansetron should be used only when steroids fail. Ondansetron toxicity is generally mild; in particular, it does not induce extrapyramidal reactions. The most frequent side-effects are headache and constipation.European Journal of Cancer 02/1993; · 5.06 Impact Factor
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ABSTRACT: GR38032F is a highly selective 5HT3-receptor antagonist which inhibits vomiting induced by cisplatin, cyclophosphamide or X-radiation in the ferret. Since cisplatin selectively increased the levels of 5HT and 5HIAA in the intestinal mucosa, a possible site of the antiemetic action of GR38032F may be on 5HT3-receptors on vagal afferents in the small intestine. The potent antiemetic action of GR38032F should be of clinical value in reducing the nausea and vomiting associated with radiotherapy or chemotherapy of cancer.Cancer Treatment Reviews 01/1988; 14(3-4):333-6. · 6.02 Impact Factor