51892-07-0Relevant academic research and scientific papers
Screening of simple carbohydrates as a renewable organocatalyst for the efficient construction of 1,3-benzoxazine scaffold
Y?ld?r?m, Ayhan,Kaya, Yunus,G?ker, Mustafa
, (2021/10/12)
A convenient protocol for the two component preparation of 1,3-benzoxazines by using several protected and unprotected carbohydrate molecules as organocatalysts have been developed which is broadly applicable to condensation reaction between variety of Ma
N-alkyl imidazole-based homonuclear coordination complex as a neutral organocatalyst for the faster and efficient construction of 3,4-dihydro-2H-1,3-oxazine scaffold
Y?ld?r?m, Ayhan,G?ker, Mustafa
, (2021/08/26)
In the present work, homonuclear coordination complex including Zn (II) and N-hexadecylimidazole ligand was used for the first time as a highly efficient homogeneous neutral organocatalyst for the synthesis of 3,4-dihydro-2H-1,3-benzoxazine monomers. Ther
Nano-Fe3O4?walnut shell/Cu(ii) as a highly effective environmentally friendly catalyst for the one-potpseudothree-component synthesis of 1,3-oxazine derivatives under solvent-free conditions
Fatemeh Mirjalili, Bi Bi,Tafti, Arefeh Dehghani
, p. 31874 - 31880 (2020/09/21)
Fe3O4?walnut shell/Cu(ii) as an eco-friendly bio-based magnetic nano-catalyst was prepared by adding CuCl2to Fe3O4?walnut shell in alkaline medium. A series of 2-aryl/alkyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazines were synthesized by the one-potpseudothree-component reaction of β-naphthol, formaldehyde and various amines using nano-Fe3O4?walnut shell/Cu(ii) at 60 °C under solvent-free conditions. The catalyst was removed from the reaction mixture by an external magnet and was reusable several times without any considerable loss of its activity. This protocol has several advantages such as excellent yields, short reaction times, clean and convenient procedure, easy work-up and use of an eco-friendly catalyst.
The modified-Mannich reaction: Conversion of arylboronic acids and subsequent coupling with paraformaldehyde and amines toward the one-pot synthesis of Mannich bases and benzoxazines
Liu, Juan,Yuan, Gaoqing
supporting information, p. 1470 - 1473 (2017/03/23)
A modified Mannich reaction has been developed for the synthesis of Mannich bases and benzoxazines via the oxidative hydroxylation of arylboronic acids and subsequent coupling with paraformaldehyde and amines in one pot. This modified Mannich reaction is easily carried out to afford the target products in good to excellent yields and tolerates a variety of functional groups.
Influence of substituent on equilibrium of benzoxazine synthesis from Mannich base and formaldehyde
Deng, Yuyuan,Zhang, Qin,Zhou, Qianhao,Zhang, Chengxi,Zhu, Rongqi,Gu, Yi
, p. 18341 - 18348 (2014/09/30)
N-Substituted aminomethylphenol (Mannich base) and 3,4-dihydro-2H-3- substituted 1,3-benzoxazine (benzoxazine) were synthesized from substituted phenol (p-cresol, phenol, p-chlorophenol), substituted aniline (p-toluidine, aniline, p-chloroaniline) and formaldehyde to study influence of substituent on equilibrium of benzoxazine synthesis from Mannich base and formaldehyde. 1H-NMR and charges of nitrogen and oxygen atoms illustrate effect of substituent on reactivity of Mannich base, while oxazine ring stability is characterized by differential scanning calorimetry (DSC) and C-O bond order. Equilibrium constants were tested from 50 °C to 80 °C, and the results show that substituent attached to phenol or aniline has same impact on reactivity of Mannich base; however, it has opposite influence on oxazine ring stability and equilibrium constant. Compared with the phenol-aniline system, electron-donating methyl on phenol or aniline increases the charge of nitrogen and oxygen atoms in Mannich base. When the methyl group is located at para position of phenol, oxazine ring stability increases, and the equilibrium constant climbs, whereas when the methyl group is located at the para position of aniline, oxazine ring stability decreases, the benzoxazine hydrolysis tends to happen and equilibrium constant is significantly low. the Partner Organisations 2014.
Synthesis and biological activity of some 3-aryl-3,4-dihydro-2h-benz[e]-1, 3-oxazines/6-bromo-3-aryl-3,4-dihydro-2h-benz[e]-1,3-oxazines
Shukla, Davender Kumar,Rani, Manju,Khan, Arif Ali,Tiwari, Kavita,Gupta, Rajinder K.
, p. 5921 - 5924 (2013/07/26)
N-(2-Hydroxy)-benzyl-arylamine (1) gives substantially pure 3-aryl-3,4-dihydro-2H-benz[e]-1,3-oxazines/6-bromo-3-aryl-3,4-dihydro-2H-benz[e] -1,3-oxazines (2) on cyclization with formaldehyde in methanol within 0.5-1.0 h at 65-68 C in excellent yields. Th
SnCl4-catalyzed aza-acetalization of aromatic aldehydes: Synthesis of aryl substituted 3,4-dihydro-2H-1,3-benzoxazines
Tang, Zilong,Chen, Weiwen,Zhu, Zhonghua,Liu, Hanwen
, p. 1372 - 1383 (2012/04/04)
Stannic tetrachloride was an efficient Lewis acid catalyst for the aza-acetalization of aromatic aldehydes with o-arylaminomethyl phenols, and a series of novel aryl substituted 3,4-dihydro-2H-1,3-benzoxazines were prepared in good yields under mild condi
New Route for the Preparation of 2H-3-Aryl-3,4-dihydro-1,3-benzoxazines and 2H-3-Aryl-3,4-dihydro-4-methyl-1,3-benzoxazines
Joglekar, S. J.,Samant, S. D.
, p. 110 - 111 (2007/10/02)
2-Hydroxybenzaldehyde (1) and 1-(2-hydroxyphenyl)ethanone (2) on reaction with different primary aromatic amines gave 2-(arylimino)methylphenols (3) and 2-phenols (4), respectively. 3 and 4 on reduction with sodium borohydride gave 2-(arylamino)methylphenols (5) and 2-phenols (6), which underwent cyclisation with formaldehyde to form 2H-3-aryl-3,4-dihydro-1,3-benzoxazines (7) and 2H-3-aryl-3,4-dihydro-4-methyl-1,3-benzoxazines (8), respectively.
