A facile and new approach to synthesize 2-amino-4-(4- amoinophenyl)-1H-1,3-diazol-1-yl- alkylaminomethanethiones Raman K. Verma Æ Monika Aggarwal Æ Manisha Bansal Æ Inder Preet Kaur Received: 24 July 2006 / Accepted: 19 January 2007 / Published online: 26 May 2007 Ó Birkha ¨user Boston 2007 Abstract An ‘‘intellectual connection’’ approach to design a facile and new syn- thesis of suitably substituted 2-aminoimidazole-based precursors of expected anti- asthmatic agents through a benzidine type of rearrangement of 2-phenylazoimidazole and subsequent coupling of the product thus obtained with alkylisothiocyanates involving a degenerative operation, thereby improving the time frame of the overall synthetic sequence, is reported. The alkylisothiocyanates required in this synthetic sequence are prepared using a best combination of reported methods. The compounds reported here can be used to produce derivatives of other biological agents. Keywords Airway hyperresponsiveness Á Alkyl-isothiocyanates Á 2-Aminoimidazole Á Antiasthmatic agents Á Benzidine Á Eosinophils Á Interleukin-5 Introduction Current therapies for asthma provide only symptomatic relief to patients and do not control inflammation. Modern treatment of asthma is directed toward lessening inflammation, thereby reducing airway reactivity and asthma severity. Recently there has been increasing clinical and experimental evidence that human eosinophils play a key role in the pathogenesis of bronchial asthma and airway hyperrespon- siveness. Once recruited from the circulation, these eosinophils are primed for ligand-mediated generation of increased amounts of cysteinyl leukotrienes and for cytotoxicity to other cells such as airway epithelium (Sanderson et al., 1985; Walker et al., 1991; Hallsworth et al., 1992; Sanderson, 1992; Walsh and Wardlaw, 1997; Park et al., 1998). R. K. Verma (&) Á M. Aggarwal Á M. Bansal Á I. P. Kaur Synthetic Organic and Medicinal Chemistry Laboratory, Department of Chemistry, Punjabi University, Patiala 147002 (Pb), India e-mail: raman_verma58@yahoo.com Med Chem Res (2007) 15:483–491 DOI 10.1007/s00044-007-9003-1