Synthesis, crystal structures and anti-inflammatory activity of fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine derivatives.

doi:10.1107/S2053229619010118

Paper

Synthesis, crystal structures and anti-inflammatory activity of fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine derivatives.

Published Jul 26, 2019 · Yue Sun, Zhong-Fei Gao, Chunhua Wang

Acta crystallographica. Section C, Structural chemistry

Q4 SJR score

15

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1

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Abstract

Two fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine (BQA) derivatives, namely 2-amino-4-(2-fluorophenyl)-9-methoxy-1,4,5,6-tetrahydrobenzo[h]quinazolin-3-ium chloride, (8), and 2-amino-4-(4-fluorophenyl)-9-methoxy-1,4,5,6-tetrahydrobenzo[h]quinazolin-3-ium chloride, (9), both C19H19FN3O+·Cl-, were generated by Michael addition reactions between guanidine hydrochloride and the α,β-unsaturated ketones (E)-2-(2-fluorobenzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, C18H15FO2, (6), and (E)-2-(4-fluorobenzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, (7). Because both sides of α,β-unsaturated ketones (6) or (7) can be attacked by guanidine, we obtained a pair of isomers in (8) and (9). Single-crystal X-ray diffraction indicates that each isomer has a chiral C atom and both (8) and (9) crystallize in the achiral space group P21/c. The chloride ion, as a hydrogen-bond acceptor, plays an important role in the formation of multiple hydrogen bonds. Thus, adjacent molecules are connected through intermolecular hydrogen bonds to generate a banded structure. Furthermore, these bands are linked into an interesting 3D network via hydrogen bonds and π-π interactions. Fortunately, the solubilities of (8) and (9) were distinctly improved and can exceed 50 mg ml-1 in water or PBS buffer system (pH 7.4) at room temperature. In addition, the results of an investigation of anti-inflammatory activity show that (8) and (9), with o- and p-fluoro substituents, respectively, display more potential for inhibitory effects on LPS-induced NO secretion than starting ketones (6) and (7).

Study Snapshot

Fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine derivatives show potential anti-inflammatory effects, with improved solubility and enhanced anti-inflammatory activity.

PopulationOlder adults (50-71 years)

Sample size24

MethodsObservational

OutcomesBody Mass Index projections

ResultsSocial networks mitigate obesity in older groups.

Synthesis, crystal structures and anti-inflammatory activity of fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine derivatives.

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