Home Crystal structure of 5-(2,2-difluoropropyl)-5-methylbenzo[4,5]imidazo[2,1-a] isoquinolin-6(5H)-one, C20H18F2N2O
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Crystal structure of 5-(2,2-difluoropropyl)-5-methylbenzo[4,5]imidazo[2,1-a] isoquinolin-6(5H)-one, C20H18F2N2O

  • Hongjuan Tong ORCID logo EMAIL logo , Xiaona Xu , Zhoujing Zhu , Yanrong Gao and Cuiya Zhang
Published/Copyright: February 19, 2025

Abstract

C20H18F2N2O, monoclinic, P21/n (no. 14), a = 10.7795(8) Å, b = 12.7526(7) Å, c = 13.4631(10) Å, β = 111.105(8)°, V = 1726.6(2) Å3, Z = 4, Rgt(F) = 0.0737 wR ref (F2) = 0.1862, T = 293 K.

CCDC no.: 2421366

Table 1 contains crystallographic data and Table 2 contains the list of the atoms including atomic coordinates and displacement parameters.

Table 1:

Data collection and handling.

Crystal: colourless plate
Size: 0.21 × 0.15 × 0.10 mm
Wavelength: Mo Kα radiation (0.71073 Å)
μ: 0.10 mm−1
Diffractometer, scan mode: Rigaku, φ and ω scans
θmax, completeness: 29.2°, 100 %
N(hkl)measured, N(hkl)unique, Rint: 19689, 4225, 0.046
Criterion for Iobs, N(hkl)gt: Iobs > 2 σ(Iobs), 2,300
N(param)refined: 229
Programs: Rigaku, 1 SHELX, 2 , 3 Olex2 4
Table 2:

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

x y z Uiso*/Ueq
F1 0.8538 (3) 0.5073 (3) 0.4103 (2) 0.1526 (13)
F2 0.6637 (3) 0.47467 (19) 0.40747 (19) 0.1385 (12)
O1 0.4223 (2) 0.59949 (18) 0.2647 (2) 0.0874 (8)
N1 0.5302 (2) 0.34805 (16) 0.07715 (16) 0.0433 (5)
N2 0.48549 (19) 0.47779 (16) 0.17250 (16) 0.0408 (5)
C1 1.0462 (3) 0.6615 (3) 0.1559 (3) 0.0680 (9)
H1A 1.122723 0.634990 0.212416 0.102*
H1B 1.034022 0.734216 0.168542 0.102*
H1C 1.059254 0.654320 0.089351 0.102*
C2 0.9243 (3) 0.6002 (2) 0.1518 (2) 0.0478 (7)
C3 0.8402 (3) 0.6374 (2) 0.2007 (2) 0.0480 (7)
H3 0.862013 0.699483 0.239444 0.058*
C4 0.7240 (2) 0.58549 (19) 0.1941 (2) 0.0415 (6)
C5 0.6921 (2) 0.49260 (18) 0.13524 (19) 0.0371 (6)
C6 0.7771 (2) 0.4543 (2) 0.0862 (2) 0.0431 (6)
H6 0.756346 0.392336 0.047263 0.052*
C7 0.8905 (3) 0.5074 (2) 0.0951 (2) 0.0489 (7)
H7 0.946381 0.480617 0.062293 0.059*
C8 0.6322 (3) 0.6320 (2) 0.2466 (2) 0.0447 (6)
C9 0.5858 (3) 0.7412 (2) 0.1969 (3) 0.0626 (9)
H9A 0.661671 0.785936 0.210115 0.094*
H9B 0.526910 0.771410 0.228155 0.094*
H9C 0.539999 0.733898 0.121472 0.094*
C10 0.7026 (3) 0.6475 (2) 0.3680 (2) 0.0537 (7)
H10A 0.777002 0.694756 0.379163 0.064*
H10B 0.640900 0.682559 0.394507 0.064*
C11 0.7540 (4) 0.5517 (3) 0.4351 (3) 0.0701 (9)
C12 0.8018 (5) 0.5663 (4) 0.5514 (3) 0.1075 (15)
H12A 0.730731 0.592566 0.571384 0.161*
H12B 0.874097 0.615470 0.572469 0.161*
H12C 0.831870 0.500290 0.585997 0.161*
C13 0.5054 (3) 0.5700 (2) 0.2303 (2) 0.0515 (7)
C14 0.5721 (2) 0.43685 (18) 0.12580 (19) 0.0370 (6)
C15 0.3805 (2) 0.40557 (19) 0.15053 (19) 0.0412 (6)
C16 0.4097 (3) 0.3267 (2) 0.0917 (2) 0.0439 (6)
C17 0.3253 (3) 0.2417 (2) 0.0561 (2) 0.0565 (8)
H17 0.342928 0.189312 0.015026 0.068*
C18 0.2141 (3) 0.2377 (3) 0.0840 (3) 0.0625 (8)
H18 0.156308 0.180970 0.062184 0.075*
C19 0.1871 (3) 0.3167 (3) 0.1439 (3) 0.0631 (9)
H19 0.111314 0.311455 0.161304 0.076*
C20 0.2686 (3) 0.4029 (2) 0.1787 (2) 0.0544 (7)
H20 0.249782 0.455933 0.218544 0.065*

1 Source of materials

The target compound was synthesized via an electrochemical method under the following typical conditions: A 20 mL test tube equipped with a stirring bar was charged with 2-methyl-1-(2-phenyl-1H-benzo[d]imidazol-1-yl)prop-2-en-1-one (0.2 mmol), sodium difluoromethanesulfinate (MeCF2 SO2 Na, 0.6 mmol), lithium perchlorate (LiClO4, 0.3 M), acetonitrile (MeCN, 4.5 mL), and water (H2O, 1.5 mL). A carbon plate (10 mm × 10 mm × 3 mm) and a platinum plate (10 mm × 10 mm × 0.2 mm) were employed as the anode and cathode, respectively. The electrolysis was performed at a constant voltage of 2.1 V at room temperature for 3 h. After completion of the reaction, the reaction mixture was extracted with ethyl acetate (EtOAc, 10 mL × 3). The combined organic layers were dried over anhydrous sodium sulfate (Na2 SO4) and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography.

2 Experimental details

Hydrogen atoms were positioned in geometrically idealized locations and refined using a riding model. The crystal structure was solved using ShelXT 2 and refined with ShelXL, 3 implemented within the Olex2 software suite 4 .

3 Comment

Benzo[4,5]imidazo[2,1-a]isoquinoline derivatives have garnered significant attention in recent years due to their diverse biological activities and potential applications in medicinal chemistry. 5 , 6 , 7 , 8 , 9 , 10 , 11 The present study focuses on the synthesis and structural elucidation of 5-(2,2-difluoropropyl) -5-methylbenzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-one.

The central benzo[4,5]imidazo[2,1-a]isoquinoline core exhibits a nearly planar conformation, with the maximum deviation from the mean plane being observed at C8 by 0.93 Å. This planarity is consistent with the conjugated aromatic system, facilitating π-π stacking interactions in the crystal. 12 , 13 , 14 , 15 , 16 , 17 The substituents at the 5-position include a 2,2-difluoropropyl group and a methyl group. The difluoropropyl group adopts an extended conformation, with the C–C–F bond angles ranging from 108.0° to 110.9°, while the C–F bond lengths are measured as 1.338(5) Å and 1.359(6) Å. The presence of the two electronegative fluorine atoms introduces notable steric and electronic effects, which influence the overall molecular packing.

The molecular packing is stabilized by a combination of π-π stacking and weak intermolecular interactions. Significant π-π stacking occurs between adjacent aromatic rings, with a centroid-to-centroid distance of 3.2 Å. Additionally, weak C–H…F interactions are observed, contributing to the stability of the three-dimensional crystal lattice.

In summary, the structural elucidation of 5-(2,2-difluoropropyl)-5-methylbenzo [4,5]imidazo[2,1-a]isoquinolin-6(5H)-one highlights the planar aromatic framework, the spatial arrangement of the fluorinated propyl group, and the key intermolecular interactions that govern its crystal packing.


Corresponding author: Hongjuan Tong, Xianyang Key Laboratory of Molecular Imaging and Drug Synthesis, School of Pharmacy, Shaanxi Institute of International Trade & Commerce, Xianyang, Shaanxi, China, E-mail:

Acknowledgments

This work was financially supported by the projects of Natural Science Foundation of Shannxi Province (2024JC–YBMS-733, 2022JM-561), the 2023 research and development project of the Xianyang Science and Technology Bureau (L2023–ZDYF–SF-030), Key Laboratory of Molecular Imaging and Drug Synthesis of Xianyang city (2021QXNL–PT-0008), Doctoral research fund project of Xianyang Vocational and Technical College (2021BK01) and the scientific research fund project of Xianyang Vocational and Technical College (2020KJB02).

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Received: 2025-01-09
Accepted: 2025-02-04
Published Online: 2025-02-19
Published in Print: 2025-06-26

© 2025 the author(s), published by De Gruyter, Berlin/Boston

This work is licensed under the Creative Commons Attribution 4.0 International License.

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