Regio- and stereo-synthesis, crystal structure and NMR assignments of N-((Z)-1-oxo-1-phenyl-3-(4-chlorophenyl)prop-2-en-2-yl)-4-nitrobenzamide

Abstract

and also the conditions employed [11,12]. Although a large variety of 1-Aroylaziridines are known to be readily isomerized into oxazolines under different conditions, [13][14][15][16][17][18] a literature survey reveals that a few examples of the isomerization of the 2-aryl keto-aziridines has been reported up to now [19][20][21][22]. Padwa and co-worker reported a pyrolytic rearrangement of trans-1,3-dibenzoyl-2-phenyl aziridine in xylene by an initial C-C bond cleavage of the aziridine ring to give a 1,3-dipolar intermediate, which rearranges to give 1,4-diphenyl-4-benzoyloxy-2-azabutadiene via a benzoyl migration (Scheme 1) [2].Our interest in the transformation of the aziridine ring [23-28] to oxazoles, thiazoles, alkenes via C-N bond or C-C bond cleavage, motivated our studies in the isomerizaton of 1,2-diaroyl-3-aryl aziridines to the derivatives of N-((Z)-1-oxo-1,3-diphenylprop-2-en-2-yl) benzamide by a C-N bond cleavage in a regioisomeric manner.The present paper describes regio-and stereo-controlled isomerization of 1,2-diaroyl-3-arylaziridines to the corresponding N-((Z)-1-oxo-1,3-diphenylprop-2-en-2-yl) benzamido in the presence of diethyl thiourea in room temperature. Results and discussionWe prepared trans-2-benzoyl-3-(4-chlorophenyl) aziridines (1) via Gabriel-Cromwell procedure [22]. Then 4-nitrobenzoyl chloride were added to a solution of trans-2-benzoyl-3-(4-chlorophenyl) aziridines (1) in the presence of Et 3 N in CH 2 Cl 2 at 0 °C to furnish 2-benzoyl-1-(4-nitrobenzoyl)-3-(4-chlorophenyl) aziridines (2) which was treated with diethyl thiourea in CH 2 Cl 2 . The reaction afforded the desired product (3) (Scheme 2) (95 %). Abstract Regio and stereo-controlled rearrangement of N-4-nitrophenyl-2-benzoyl-3-(4-Cl phenyl) aziridine to N-((Z)-1-oxo-1-phenyl-3-(4-chlorophenyl)prop-2-en-2-yl)-4 nitrobenzamide is described. The studies on the single crystal X-ray diffraction method confirmed the stereochemistry of the product and the proposed mechanism. The product was crystallized in yellow crystal 0.30 × 0.10 × 0.10 mm, a = 10.0267 (5) Å, b = 16.1419 (9) Å, c = 23.9254 (14) Å, V = 3872.3(4) Å 3 , ρ(calcd) = 1.396 mg cm −3 , μ = 0.229 mm −1 , Z = 8, λ = 0.71073 Å, T = 301 K, ω and ϕ scans, 3591 reflections collected (±h, ±k, ±l), [I ≥ 2 σ(I)], 1959 independent (R int = 0.0808) and 1852 observed reflections [I ≥ 2 σ(I)], 267 refined parameters, R = 0.0544, wR 2 = 0.1260, max residual electron density 0.251 (−0.373) e Å −3 , Flack parameter 0.0040 (6).