52401-41-9

Upstream product

• 91-16-7 1,2-dimethoxybenzene 
• 5333-34-6 3-(3,4-dimethoxybenzoyl)propionic acid 
• 120-14-9 3,4-dimethoxy-benzaldehyde 
• 137744-82-2 C₁₂H₁₄O₄ 
• 13575-74-1 4-(3,4-dimethoxyphenyl)butanoic acid 
• 13575-75-2 6,7-dimethoxy-1-oxo-1,2,3,4-tetrahydronaphthalene 

Downstream Products

• 52401-42-0 1-amino-6,7-dimethoxynaphthalene 
• 10103-06-7 2,3-dimethoxynaphthalene 

Relevant academic research and scientific papers

Design, synthesis and biological evaluation of brain penetrant benzazepine-based histone deacetylase 6 inhibitors for alleviating stroke-induced brain infarction

Histone deacetylase 6 (HDAC6) has become a promising therapeutic target for central nervous system diseases due to its more complex protein structure and biological functions. However, low brain penetration of reported HDAC6 inhibitors limits its clinical application in neurological disorders. Therefore, the benzazepine, a brain-penetrant rigid fragment, was utilized to design a series of selective HDAC6 inhibitors to improve brain bioavailability. Various synthetic strategies were applied to assemble the tetrahydro-benzazepine ring, and 22 compounds were synthesized. Among them, compound 5 showed low nanomolar potency and strong isozyme selectivity for the inhibition of HDAC6 (IC50 = 1.8 nM, 141-fold selectivity over HDAC1) with efficient binding patterns like coordination with the zinc ion and π-π stacking effect. Western blot results showed it could efficiently transport into SH-SY5Y cells and selectively enhance the acetylation level of α-tubulin with a moderate effect on Histone H3. Notably, pharmacokinetic studies demonstrated that compound 5 (brain/plasma ratio of 2.30) had an excellent ability to penetrate the blood-brain barrier of C57 mice. In male rats with transient middle cerebral artery occlusion (MCAO), compound 5 significantly reduced the cerebral infarction from 21.22% to 11.47% and alleviated neurobehavioral deficits in post-ischemic treatment, which provided a strong rationale for pursuing HDAC6-based therapies for ischemic stroke.

Highly enantioselective [3+2] coupling of cyclic enamides with quinone monoimines promoted by a chiral phosphoric acid

Enantioselective [3+2] coupling of cyclic enamides with quinone monoimines was realised using a chiral phosphoric acid as a catalyst. This transformation allowed for the synthesis of highly enantioenriched polycyclic 2,3-dihydrobenzofurans (up to 99.9% ee). The absolute configuration of one product was determined by an X-ray crystal structural analysis. We also found a possible mechanism for this reaction.

Expeditious approach to pyrrolophenanthridones, phenanthridines, and benzo[ c ]phenanthridines via organocatalytic direct biaryl-coupling promoted by potassium tert -butoxide

A methodology involving a "transition metal-free" intramolecular biaryl-coupling of o-halo-N-arylbenzylamines has been developed in the presence of potassium tert-butoxide and an organic molecule as catalyst. The reaction appears to proceed through KOtBu-promoted intramolecular homolytic aromatic substitution (HAS). Interestingly, this biaryl coupling also works in the presence of potassium tert-butoxide as sole promoter. On extending our approach further, we found that N-acyl 2-bromo-N-arylbenzylamines undergo a one-pot N-deprotection/biaryl coupling followed by oxidation, thus offering an expeditious route to the phenanthridine and benzo[c]phenanthridine skeletons. The strategy has been applied to a concise synthesis of Amaryllidaceae alkaloids viz. oxoassoanine (1b), anhydrolycorinone (1d), 5,6-dihydrobicolorine (2d), trispheridine (2b), and benzo[c]phenanthridines alkaloids dihydronitidine (3b), dihydrochelerythidine (3d), dihydroavicine (3f), nornitidine (3h), and norchelerythrine (3j).

Pd-catalyzed Semmler-Wolff reactions for the conversion of substituted cyclohexenone oximes to primary anilines

Homogeneous Pd catalysts have been identified for the conversion of cyclohexenone and tetralone O-pivaloyl oximes to the corresponding primary anilines and 1-aminonaphthalenes. This method is inspired by the Semmler-Wolff reaction, a classic method that exhibits limited synthetic utility owing to its forcing conditions, narrow scope, and low product yields. The oxime N-O bond undergoes oxidative addition to Pd0(PCy3)2, and the product of this step has been characterized by X-ray crystallography and shown to undergo dehydrogenation to afford the aniline product.

Direct arylation of cyclic enamides via Pd(ii)-catalyzed C-H activation

A new direct coupling of cyclic enamides with aryl boronic acids via Pd(ii)-catalyzed C-H functionalization has been achieved with good yields (up to 90%).