Piperazine amidines as antiviral agents

#This disclosure provides compounds having drug and bio-affecting properties, their pharmaceutical compositions and method of use. In particular, the disclosure is concerned with indole and azaindole piperazine diamide derivatives that possess unique antiviral activity. More particularly, the present disclosure relates to compounds useful for the treatment of HIV and AIDS.

#HIV-1 (human immunodeficiency virus-1) infection remains a major medical problem, with an estimated 42 million people infected worldwide at the end of 2002. The number of cases of HIV and AIDS (acquired immunodeficiency syndrome) has risen rapidly. In 2002, approximately 5.0 million new infections were reported, and 3.1 million people died from AIDS. Currently available drugs for the treatment of HIV include nucleoside reverse transcriptase (RT) inhibitors or approved single pill combinations: zidovudine (or AZT or Retrovir®), didanosine (or Videx®), stavudine (or Zerit®), lamivudine (or 3TC or Epivir®), zalcitabine (or DDC or Hivid®), abacavir succinate (or Ziagen®), Tenofovir disoproxil fumarate salt (or Viread®), emtricitabine (or FTC), Combivir® (contains −3TC plus AZT), Trizivir® (contains abacavir, lamivudine, and zidovudine), Epzicom® (contains abacavir and lamivudine), Truvada® (contains Viread® and emtricitabine); non-nucleoside reverse transcriptase inhibitors: nevirapine (or Viramune®), delavirdine (or Rescriptor®) and efavirenz (or Sustiva®), and peptidomimetic protease inhibitors or approved formulations: saquinavir, indinavir, ritonavir, nelfinavir, amprenavir, lopinavir, and Kaletra®(lopinavir and Ritonavir). Each of these drugs can only transiently restrain viral replication if used alone. However, when used in combination, these drugs have a profound effect on viremia and disease progression. In fact, significant reductions in death rates among AIDS patients have been recently documented as a consequence of the widespread application of combination therapy. However, despite these impressive results, 30 to 50% of patients ultimately fail combination drug therapies. Insufficient drug potency, non-compliance, restricted tissue penetration and drug-specific limitations within certain cell types (e.g. most nucleoside analogs cannot be phosphorylated in resting cells) may account for the incomplete suppression of sensitive viruses. Furthermore, the high replication rate and rapid turnover of HIV-1 combined with the frequent incorporation of mutations, leads to the appearance of drug-resistant variants and treatment failures when sub-optimal drug concentrations are present. Therefore, novel anti-HIV agents exhibiting distinct resistance patterns, and favorable pharmacokinetic as well as safety profiles are needed to provide more treatment options. Improved HIV fusion inhibitors and HIV entry coreceptor antagonists are two examples of new classes of anti-HIV agents currently being studied by a number of investigators.

#The properties of a class of HIV entry inhibitors called HIV attachment inhibitors has been improved in an effort to obtain compounds with maximized utility and efficacy as antiviral agents. A disclosure describing indoles of which the structure shown below for BMS-705 is representative has been disclosed [Antiviral Indoleoxoacetyl Piperazine Derivatives. Wade Blair; Millind Deshpande; Haiquan Fang; Ping-Fang Lin; Tim Spencer; Owen Wallace; Hui Wang; Tao Wang; Zhongxing Zhang and Kap-Sun Yeung WO-00076521 (U.S. Pat. No. 6,469,006 issued), 2000].

#Continued efforts to search for compounds with improved anti-HIV capabilities have led to the discovery that piperazine amidines can be substituted onto the substituted azaindole oxoacetyl or indole oxoacetyl moieties to provide useful antiviral compounds of this disclosure as depicted by the general formula shown below.

#The inventors of the present disclosures have investigated the utility of the piperidine amidines in combination with other groups that have previously been used to replace the indoles and azaindoles in previous piperazine benzamide work. Compounds with useful antiviral properties have been obtained.

#Since the compounds of the present disclosure may possess asymmetric centers, the present disclosure includes the individual diastereoisomeric and enantiomeric forms of the compounds of Formula I in addition to the mixtures thereof.