The crystal structure of N , N -(ethane-1,1-diyl) dibenzamide, C 16 H 16 N 2 O 2

C 16 H 16 N 2 O 2 , orthorhombic, P 2 1 2 1 2 1 (no. 19), a = 9.370(2) Å, b = 10.265(2) Å, c = 15.863(4) Å, V = 1525.8(6) Å 3 , Z = 4, R gt ( F ) = 0.0753, wR ref ( F 2 ) = 0.198, T = 273 K.

1 Source of materials Benzamide (0.3 mmol, 36.3 mg) and ferric chloride (2.4 mg, 5 %) were added into a 10 mL screw-cap bottle, air in the screw-cap bottle was replaced with nitrogen via a Schlenk apparatus, then a tert-butyl hydroperoxide (0.9 mmol, 165 μL) solution (3 mL, diethyl ether:acetonitrile = 1:1) was added using a syringe.Then, the above reaction bottle was placed under a LED lamp of 20 W (wavelength = 450-455 nm) for illumination for 20 h.After completion of the reaction, the reaction solution was extracted three times with ethyl acetate and water, and an obtained mixture was dried and concentrated and subjected to chromatography using a silica gel column (an eluent was petroleum ether:ethyl acetate = 5:1 to 2:1), and 14 mg of product I was obtained with a yield of 35 %.
The crystal was prepared using a volatile compound saturated solution method.Specific preparation steps were as follows.0.27 g (about 1 mmol) of the title compound was dissolved in 10 mL of dichloromethane to obtain a colorless transparent solution, then the colorless transparent solution was stood at room temperature (20 °C to 40 °C) for natural volatilization.A colorless transparent needle single crystal at the bottom of a cup was the crystal of the geminal diamide compound.

Experimental details
Single-crystal X-ray diffraction measurements were carried out on a Rigaku Mercury CCD diffractometer at low temperature.After absorption correction, the crystal structure was solved using the Olex2 software 1  SHELXT 2 program and refined with SHELXL. 3All hydrogens were generated geometrically (C-H bond fixed at 0.96 Å), and allowed to ride on their parent carbon atoms.

Comment
Diamides are a type of amides which contain two amide functional groups that are interconnected to each other via a single methylene bridge.They are a powerful but rare class of compounds. 5Due to their unique chemical properties, bisamides have garnered widespread interest in the fields of organic synthesis, drug development, and materials science.
][8] These compounds are typically synthesized through condensation reactions between compounds with active hydrogen, such as benzamides or aldehydes.The title compound was prepared by heating the aldehyde and acetamide to generate corresponding products, 9 the related compounds and the same methods were reported with different catalysts, such as triflic acid, 10 fuoroalkanesulfonic acid, 11 p-toluene sulfonic acid, 12 B(HSO 4 ) 3 , 13 reusable hydroxyapatite. 14We have innovated the synthetic method by employing a green photocatalytic approach, utilizing the inexpensive ferric chloride as a photocatalyst, to directly react amides with ethers under visible light irradiation, achieving the synthesis of gem-diamide compounds efficiently.
In the title structure, a C 1 -C 6 benzene ring plane and a C 11 -C 16 benzene ring plane forms an included angle of 48.8°.There are two intermolecular hydrogen bonding interactions involving the amino N and the corresponding carboxylate oxygen O in neighboring molecules with bond lengths of NH⋯O ranging from 2.84-2.92Å which is basically consistent with the literature. 15able : Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å  ).

Atom
x y z U iso */U eq

Table  :
Data collection and handling.