Yang, Jian; Wang, Xin; El-Harairy, Ahmed; Bai, Rongxian; Gu, Yanlong published the artcile< Bronsted acid-catalyzed facile synthesis of α-substituted N-arylaminoacetals and their downstream conversions to functionalized pyrroles>, Synthetic Route of 94-02-0, the main research area is glyoxal dimethyl acetal arylamine ketone Mannich Bronsted acid catalyst; aryl aminoacetal preparation dicarbonyl compound cyclization; pyrrole preparation.
The α-substituted N-arylaminoacetals RNHCH(CH(OCH3)2)CH2C(O)R1 (R = Ph, 3,4-difluorophenyl, 2-chlorophenyl, etc.; R1 = Me, Ph, thiophen-2-yl, etc.) are important building blocks for organic synthesis, which can be synthesized via Mannich reaction by using glyoxal di-Me acetal as a key precursor. As the acetal fragment was known to be susceptible to acid, in literature methods, the Mannich reaction was performed under either neutral or gently acidic conditions. As a result, only a few kinds of α-substituted N-arylaminoacetals have been synthesized via Mannich reaction until now. The Mannich adducts of glyoxal di-Me acetal, arylamines RNH2 and ketones CH3C(O)R1 are quite stable toward strong Bronsted acid. This led to use successfully p-toluenesulfonic acid as the acid catalyst to synthesize a broad range of α-substituted N-arylaminoacetals. The Mannich adducts could be obtained in good to excellent yields. Particularly, these products were demonstrated to be able to react with 1,3-dicarbonyl compounds R2C(O)CH2C(O)R3 [R2 = OCH3, Me, (4-methoxyphenyl)aminyl, etc.; R3 = H, Me, n-Bu, Ph, i-Pr] in the presence of Sc(OTf)3 catalyst. A special class of multi-substituted pyrroles I (R1 = Me, Ph) was thus synthesized and can be converted to some important heterocyclic compounds including Me 2,6-dimethyl-1-(4-methylphenyl)-5-phenyl-1H-indole-3-carboxylate and Me 5-formyl-2-methyl-1-(4-methylphenyl)-1H-pyrrole-3-carboxylate. Di-Me acetals of quinoline-2-carbaldehydes II (R4 = OCH3, H; R5 = H, OCH3; R6 = OCH3; R6R7 = -CH=CH-CH=CH-; R5R6 = -CH=CH-CH=CH-) were also synthesized via one-pot three-component reactions of glyoxal di-Me acetal, electron-rich anilines 3-R4-4-R5-5-R6-6-R7CHNH2 and acetone.
Molecular Catalysis published new progress about 1,3-Dicarbonyl compounds Role: RCT (Reactant), RACT (Reactant or Reagent). 94-02-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H12O3, Synthetic Route of 94-02-0.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics