59168-22-8

Upstream product

• 120-20-7 2-(3,4-dimethoxyphenyl)-ethylamine 
• 703-59-3 homophthalic anhydride 
• 4456-77-3 4H-isoquinolin-1,3-dione 
• 7417-21-2 2-(3,4-dimethoxyphenyl)ethyl alcohol 

Downstream Products

• 182552-79-0 2-[2-(3,4-Dimethoxy-phenyl)-ethyl]-4,4-dimethyl-4H-isoquinoline-1,3-dione 
• 47206-72-4 2,3-dimethoxyberbine 

Relevant academic research and scientific papers

N-acyliminium ion cyclisation versus rearrangement. The synthesis of 13,13-dimethylberberines and 3,4-dimethylisoquinolin-1-ones

The regioselective reduction of a range of N-substituted-4,4- dimethylhomophthalimide derivatives gave the related carbinol amides that function as acyliminium ion precursors in the presence of Lewis or protic acids; the fate of the acyliminium ions is de

Metalation vs Nucleophilic Addition in the Reactions of N-Phenethylimides with Organolithium Reagents. Ready Access to Isoquinoline Derivatives via N-Acyliminium Ions and Parham-Type Cyclizations

Sequential carbophilic addition of organolithium reagents and N-acyliminium ion cyclization of N-phenethylimides 1 affords the substituted isoquinolones 3 in high yields, with the possibility of varying the substituent at the C-1 position of the isoquinoline ring by changing the organolithium reagent. Ready access to the isoquinoline nucleus via Parham-type cyclization of imides 2 is also described. We have shown that iodinated imides 2 tolerate the metal-halogen exchange in the presence of the imide group, and the intramolecular cyclization of the so-obtained aromatic organometallic derivatives leads to the corresponding enamides 4. Both approaches have allowed the efficient preparation of various types of the isoquinoline class of alkaloids, just by changing the substitution pattern on the readily available starting imides. Thus, we have developed convenient alternative routes for the synthesis of benzo[a]quinolizidones and their 2-oxa analogs, isoindoloisoquinolones, dibenzo[a,h]quinolizidones, and thiazolo- and oxazolo[4,3-a]isoquinolones.

Parham-type cyclization and nucleophilic addition-N-acyliminium ion cyclization sequences for the construction of the isoquinoline nucleus

Efficient methodologies based on the nucleophilic addition-N-acyliminium ion cyclization and the Parham-type cyclization sequences of N-phenethylimides 1 and 2 are reported for the synthesis of a dibenzo[a,h]quinolizidones, thiazolo-, oxazolo-, and imidazolo[4,3-a]isoquinolones.

Improved synthesis of Protoberberine Type Alkaloids

An improved synthesis of protoberberine type of compounds is described.The amido acid (IIa) obtained by the condensation of homoveratrylamine and homophthalic acid anhydride undergoes cyclisation in the presence of PPA to give 5,6-dihydro-2,3-dimethoxy-8-