6772-68-5

Upstream product

• 4385-35-7 isochroman-3-one 
• 62-53-3 aniline 
• 10602-08-1 2-ethynylbenzyl alcohol 
• 77123-58-1 2-[2-(trimethylsilyl)ethynyl]benzaldehyde 
• 6630-33-7 ortho-bromobenzaldehyde 
• 63969-83-5 2-formylphenylacetic acid methyl ester 

Relevant academic research and scientific papers

Synthetic approaches to N- and 4-substituted 1,4-dihydro-3(2H)-isoquinolinone derivatives

Reaction of methyl-2-(2-formylphenyl)acetate with primary amines in a reductive amination/cyclisation process resulted in N-substituted 1,4-dihydro-3(2H)-isoquinolinones. With H2NCH2R sodium borohyride is a suitable reductant (11 examples), but H2NCHR1R2 required a transfer hydrogenation using ammonium formate catalysed by palladium on carbon (9 examples). 4-Substituted-1,4-dihydro-3(2H)-isoquinolinones were synthesised by deprotonation (n-butyllithium) and addition of R3CH2Br (12 examples with R3 = alkyl, Ar, CH[dbnd]CH2, C[tbnd]CH). Modest diastereoselectivity was achieved with 1,4-dihydro-3(2H)-isoquinolinones derived from H2NCHMeR2 [R2 = (η5-C5H4)Co(η4-C4Ph4) - max. dr = 1.9 : 1], but use of H2NCHMeFc (Fc = ferrocenyl) provided a new method of 1,4-dihydro-3(2H)-isoquinolinone N-deprotection with formic acid.

A new and facile approach to 1,2-dihydroisoquinolin-3(4: H)-imines by the Cu(i)-catalyzed reaction of 2-ethynylbenzyl methanesulfonates, sulfonyl azides and amines

A new, step-economical and operationally simple access to unsubstituted 1,2-dihydroisoquinolin-3(4H)-imines by Cu-catalyzed MCRs under mild conditions is described. In addition, selective hydrolysis of imines to the corresponding 1,2-dihydroisoquinolin-3(4H)-ones under refluxed conc. HCl has also been investigated.

Synthetic approaches to 2-substituted 1-oxo- and 3-oxotetrahydroisoquinolines

2-Substituted homophthalimides 2a-c were reduced regioselectively with sodium borohydride to carbinol-lactam intermediates 3a-c, which were dehydrated, followed by hydrogenation, to give 1-oxotetrahydroisoquinolines or 3,4-dihydroisoquinolin-1(2H)ones 5a-c. The isomeric 3-oxo-tetrahydroisoquinolines or 1,4-dihydroisoquinolin-3(2H)-ones 8a-i were obtained in satisfactory yields via heating 3-isochromanone (6) with the corresponding amines 7a-i in the presence of aluminum chloride.