Heterophase N-aminomethylation of 5-arylidenepseudothiohydantoins by arylamines and aqueous formaldehyde in aromatic solvents: Effect of substituents in the heterocyclic substrate and the aryl amine on the efficiency of the process

Abstract

with aqueous formaldehyde and aromatic amines in benzene or toluene. We explain the effect of substituents in the heterocyclic substrate and the aryl amine on the efficiency of the process within a detailed scheme for one of the possible aminomethylation reaction routes.

Synthesis of bis-spirocoupled pyrrolidinooxindoles derived from isatinylidene derivatives of thiazolotriazinones by [3+2] dipolar cycloaddition

“…We have studied reactions of 3 aryl 3,4 dihydro 2H [1,3]thiazolo [3,2 a] [1,3,5]triazin 6(7H) ones 2 with N methylisatine derivatives 4a-c (Scheme 2). The con densation was carried out in methanol in the presence of 40% aqueous KOH in catalytic amounts to give (7Z) 3 aryl 7 (2 oxo 1,2 dihydro 3H indol 3 ylidene) 3,4 di hydro 2H [1,3]thiazolo [3,2 a] [1,3,5]triazin 6(7H) ones 5a-d in good yields.…”

“…The con densation was carried out in methanol in the presence of 40% aqueous KOH in catalytic amounts to give (7Z) 3 aryl 7 (2 oxo 1,2 dihydro 3H indol 3 ylidene) 3,4 di hydro 2H [1,3]thiazolo [3,2 a] [1,3,5]triazin 6(7H) ones 5a-d in good yields.…”

“…

Isatines react with 3,4 dihydro 2H [1,3]thiazolo[3,2 a] [1,3,5]triazin 6(7H) ones to give their isatinylidene derivatives, which add azomethinylide, generated in situ from paraform aldehide and sarcosine, to yield bis spirocoupled derivatives of pyrrolidine. The [3+2] dipolar cycloaddition reactions studied proceed absolutely diastereoselectively.

It is known 1-3 that pseudothiohidantoin 1 reacts with primary aliphatic and aromatic amines in the presence of formaldehyde to form 3,4 dihydro 2H [1,3]thiazolo [3,2 a][1,3,5]triazin 6(7H) ones 2, which, possessing an active methylene group, readily form with aromatic alde hydes arylidene derivatives 3 (Scheme 1).

Scheme 1 R = Alk, Ar

We have studied reactions of 3 aryl 3,4 dihydro 2H [1,3]thiazolo[3,2 a][1,3,5]triazin 6(7H) ones 2 with N methylisatine derivatives 4a-c (Scheme 2).

…”

“…Isatines react with 3,4 dihydro 2H [1,3]thiazolo[3,2 a] [1,3,5]triazin 6(7H) ones to give their isatinylidene derivatives, which add azomethinylide, generated in situ from paraform aldehide and sarcosine, to yield bis spirocoupled derivatives of pyrrolidine. The [3+2] dipolar cycloaddition reactions studied proceed absolutely diastereoselectively.…”

“…It is known 1-3 that pseudothiohidantoin 1 reacts with primary aliphatic and aromatic amines in the presence of formaldehyde to form 3,4 dihydro 2H [1,3]thiazolo [3,2 a] [1,3,5]triazin 6(7H) ones 2, which, possessing an active methylene group, readily form with aromatic alde hydes arylidene derivatives 3 (Scheme 1).…”