+ Models CCLET-1911; No. of Pages 4 Please cite this article in press as: M.S. Mane, et al., Chin. Chem. Lett. (2011), doi:10.1016/j.cclet.2011.03.016 Regiospecific oxidation of an alkyl group of aromatic amine to carbonyl group by DDQ in aq. medium Madhav S. Mane a , Ravi S. Balaskar a , Sandip N. Gavade a , Pramod N. Pabrekar c , Murlidhar S. Shingare b , Dhananjay V. Mane a, * a Organic Research Laboratory, S.C.S. College, Omerga, 413 606, MS, India b Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, 431 004, MS, India c V.G. Vaze College, Mulund(E), Mumbai, 400081, MS, India Received 6 December 2010 Abstract The regiospecific oxidation of alkyl group of both sterically hindered and unhindered aromatic amine to corresponding carbonyl compound was done in aq. medium by using DDQ. The optimized reaction protocol was found to be most simple, high yielding and novel method for oxidation of alkyl group of aromatic amine in to its carbonyl compound. # 2011 Dhananjay V. Mane. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: DDQ; Aq. medium; Regiospecific oxidation; Aromatic amine The discovery of new environment friendly methods for selective catalytic oxidation of alkyl substrates to aldehyde and ketone in presence of amine is an important goal in the development of modern methods for chemical synthesis [1]. With the considerable development of selective organic chemistry in the last few decades; specific reagents have seen their potential increase dramatically. The spectrum of their applications in modern organic chemistry has been enlarged to offer new challenging synthesis opportunities [2]. Not an exception, DDQ has been investigated as a powerful oxidizing agent by several research groups, and was proved to be useful for a wide range of reactions. Although several uses of DDQ have been mentioned in many patents from the pharmaceutical and chemical specialties industries, we will restrict this article to regiospecific oxidation by DDQ of an unhindered alkyl group of aromatic amine. Amino benzaldehydes are the important key intermediates for synthesis of many biologically active compounds. They are used for the synthesis of inosine monophosphate dehydrogenase (IMPDH) inhibitors [3] in development of anticancer drugs [4], Chk1 kinase inhibitors [5] and also in the preparation of an intermediate of one of the major metabolites of the antihypertensive trequisin [6], novel thyroid hormone receptor antagonists [7]. The oxidation of the sterically hindered aromatic amine has been reported using enzymatic [8], electrochemical [9] and chemical reactions [10,11]. In the reaction the nitrogen of the molecule is involved in the oxidation and not the www.elsevier.com/locate/cclet Available online at www.sciencedirect.com Chinese Chemical Letters xxx (2011) xxx–xxx * Corresponding author. E-mail address: dr_dvmane@rediffmail.com (D.V. Mane). 1001-8417/$ – see front matter # 2011 Dhananjay V. Mane. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2011.03.016