Application of Cyano-aci-Nitroacetate to Organic Syntheses. 1. Facile Synthesis of Pentanedinitrile-2,4-dinitronates.

Abstract

Pentanedinitrile (glutaronitrile) and its derivatives are widely used as functional materials including biologically active compounds1 and employed as excellent precursors for azaheterocycles,2 polymers, and so on.3 Hence, novel functionalization of pentanedinitrile and development of facile preparative methods for their preparation are highly demanding subjects. Pentanedinitrile-2,4-dinitronate 14 has been investigated for its antitumor activity. 2-Aryl (or alkyl) pentanedinitrile-2,4-dinitronates are prepared through twostep reactions from nitroacetonitrile. The condensation of nitroacetonitrile with aldehydes in the presence of thionyl chloride gives R-nitroacrylonitriles 2. The succeeding treatment of 2 with amine leads to dinitronates 1. It is known that the condensation of nitroacetonitrile with triethyl orthoformate in the presence of thionyl chloride also gives 4-nitropentanedinitrile-2-nitronate.5 These procedures are, however, somewhat troublesome and are not able to afford 3,3-disubstituted dinitronates. Meanwhile, we have been paid attention to 4-nitroisoxazolin-5(2H)-ones that show multifunctionalities. Readily available pyridinium salt 36,7 reacts with electrophiles giving N-methyl derivative 4a and N-acetyl 4b (Scheme 1). The former is effectively converted to functionalized nitrile oxide8 and polysubstituted pyrroles.9 The latter behaves as the mild acylating agent.10 Furthermore,