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Rajachandrasekhar V.,CiVentiChem India Private Ltd | Vineel B.G.,CiVentiChem India Private Ltd | Venkataiaha S.,Jawaharlal Nehru Technological University | Dubey P.K.,Jawaharlal Nehru Technological University
Asian Journal of Chemistry | Year: 2014

Commercially available 2-amino-4-nitrophenol (1) was treated with chloroacetyl chloride to obtain 6-nitro-4H-benzo[1,4]oxazine-3,2- one (2). The latter was reacted with ethyl 3-bromopropionate to obtain 3-(6-nitro-3-oxo-2,3-dihydrobenzo[1,4]oxazine-4-yl)propionic acid ethyl ester (3), which on treatment with lithium aluminiumhydride gave 6-nitro-3,4,10,10a-tetrahydro-2H-1,9-dioxo-4aazaphenanthrene (4) by reductive cyclization. Compound, 4 was treated with H2/Pd-C containing di-tert-butyldicarbonate (Boc)2O in THF to obtain the (3,4,10,10a-tetrahydro-2H-1,9-dioxa-4a-azaphenanthrene-6-yl)carbamic acid tert-butyl ester (5). The latter, on treatment with alkyl or arylsulfonyl chlorides in the presence of NaH gave N-(3,4,10,10a-tetrahydro-2H-1,9-dioxa-4a-azaphenanthrene-6-yl) alkyl or aryl sulfonamide-N1-carbamic acid tert-butyl ester (6). N-Boc group of 6 was de-protected with Cs2CO3/imidazole in acetonitrile to give the title compounds N-(3,4,10,10a-tetrahydro-2H-1,9-dioxa-4a-azaphenanthrene-6-yl) alkyl or aryl sulfonamides (7) as potential antibacterial agents. All the new products obtained in the above sequences of reactions have been adequately characterized by spectral data.

Rajachandrashekar V.,CiVentiChem India Private Ltd | George Vineel B.,CiVentiChem India Private Ltd | Venkataiah S.,CiVentiChem India Private Ltd | Dubey P.K.,University of Hyderabad
Der Pharma Chemica | Year: 2014

Commercially available 2-nitrophenol 1 was treated with ethyl bromoacetate to obtain the (2-ntrophenoxy)acetic acid ethyl ester (2). Then, 2 was reduced with Fe/AcOH to yield 4H-benzo[1,4]oxazin-3-one (3), which on treatment with ethyl 3-bromopropionate led to the formation of 3-(3-oxo-2,3-dihydrobenzo[1,4]oxazin-4-yl)propionic acid ethyl ester (4). Reduction of 4 with lithium aluminiumhydride gave 3,4,10,10a-tetrahydro-2H-1,9-dioxa-4aazaphenanthrene (5). All the new products obtained in the above sequences of reactions have been adequately characterized by spectral data.

Rajitha C.,CiVentiChem India Private Ltd | Rajitha C.,Jawaharlal Nehru Technological University Anantapur | Dubey P.K.,Jawaharlal Nehru Technological University Anantapur | Sunku V.,CiVentiChem India Private Ltd | And 2 more authors.
Journal of Heterocyclic Chemistry | Year: 2013

The synthesis of novel 1,2,3-thiadiazol derivatives containing 2H-benzo[b][1,4]oxazin-3(4H)-one moiety as one of the substituents has been reported. A combined application of H3PO4/(CF 3CO)2O mediated acylation followed by Hurd-Mori reaction has been explored to synthesize these compounds. The scope and limitation of this strategy along with the reaction mechanism of the key step is discussed. © 2013 HeteroCorporation.

Shyamsunder Reddy T.,CiVentiChem India Private Ltd | Shyamsunder Reddy T.,Jawaharlal Nehru Technological University Anantapur | Shiva Kumar K.,University of Hyderabad | Meda C.L.T.,University of Hyderabad | And 12 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2012

A number of novel 1,8-disubstituted 5,5-dimethyl-4,5-dihydro-1H-benzo[g] indazoles based on a conformationally restricted pyrazole framework have been designed as potential inhibitors of PDE4. All these compounds were readily prepared by using simple chemistry strategy. The in vitro PDE4B inhibitory properties and molecular modeling studies of some of the compounds synthesized along with the X-ray single crystal data of a representative compound is presented. © 2012 Elsevier Ltd. All rights reserved.

Reddy S.S.,CiVentiChem India Private Ltd | Vineel B.G.,CiVentiChem India Private Ltd | Venkataiah S.,CiVentiChem India Private Ltd | Naidu A.,Jawaharlal Nehru University | Dubey P.K.,Jawaharlal Nehru University
Asian Journal of Chemistry | Year: 2014

Isopropyl azide (1) was reacted with cyanoacetamide (2) in the presence of sodium ethoxide to obtain 4-amino-3-isopropyl-3H-[1,2,3]triazolo-5-carboxamide (3) which on treatment with excess of diethyl carbonate and sodium ethoxide gave 3-isopropyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7-diol (4). The latter on treatment with POCl3 and 2,6-lutidine in the presence of catalytic amount of PCl5 resulted in 5,7-dichloro-3-isopropyl-3H-[1,2,3]triazolo[4,5-d] pyrimidine (5) in good yields. Compound 5 on condensation with L-prolinol (6) in ethanol yielded (S)- [1-(5-chloro-3-isopropyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-7-yl)pyrrolidine-2-yl-meth anol (7). Compound 7 on treatment with anilines (8a-8j) gave (S)-(1-(3-isopropyl-5-(arylamino)-3H-[1,2,3]triazolo[4,5-d]pyrimidine-7-yl)pyrrolidine-2-yl) methanol (9a-j) by the nucleophilic displacement of the chlorine at 5th-position. 9a-j on treatment with POCl3 afforded a series of novel chiral derivatives of (S)-N-(3-isopropyl-7a,8,9,10[1′2′:3,4]imidazolo[1,2c] [1,2,3]triazolo[4,5e]pyrimidine5(7H)yl-idine) aniline hydrochloride (10a-j) by dehydrative cyclization. This cyclization also takes place with SOCl2 under refluxing conditions, but yields are low compared to the POCl3 conditions. © 2014, Chemical Publishing Co. All rights reserved.

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