Simple and efficient synthesis of 4H-3,1-benzoxazines from 2-bromomethylphenyl isocyanate and amines

1990 ◽  
Vol 55 (3) ◽  
pp. 752-760 ◽  
Author(s):  
Jozef Gonda ◽  
Mariana Barnikol
Keyword(s):  
Elemental Analysis ◽  
Spectral Methods ◽  
Aromatic Amines ◽  
Sodium Hydrogen Carbonate ◽  
Sodium Hydride ◽  
Efficient Synthesis ◽  
Alkyl Aryl ◽  
Sodium Hydrogen ◽  
Radical Bromination ◽  
Hydrogen Carbonate

Reaction of 2-bromomethylphenyl isocyanate (II; prepared by radical bromination of 2-tolyl isocyanate with N-bromsuccinimide) with aliphatic and aromatic amines takes place on the NCO group under formation of stable N-alkyl(aryl)-N'-(2-bromomethylphenyl)ureas III. On treatment with sodium hydrogen carbonate in water or sodium hydride in N,N-dimethylformamide, the ureas III are cyclized to give 2-alkyl(aryl)amino-4H-3,1-benzoxazines IV in good yields. Reaction of isocyanate II with alcohols leads to alkyl 2-bromomethylphenyl carbamates. Structure of the synthesized compounds has been proven by spectral methods and elemental analysis.

scholarly journals Experiments towards the Synthesis of the Ergot Alkaloids and Related Structures. Part 7.1 Novel Syntheses of some 4-Acyl-2,3,4,4a,5,6-hexahydrobenzo[f]quinolin-2-ones

1999 ◽  
Vol 23 (2) ◽  
pp. 94-95
Author(s):  
Mark A. E. Bowman ◽  
Ralph E. Bowman
Keyword(s):  
Sodium Hydrogen Carbonate ◽  
Ergot Alkaloids ◽  
Aqueous Sodium ◽  
Sodium Hydrogen ◽  
Hydrogen Carbonate ◽  
Aqueous Sodium Hydrogen Carbonate

Reaction of the N-formyl enol-lactone 4 and the corresponding N-acetyl 10 and N-methoxycarbonyl 11 derivatives with bis(trimethylsilyl)potassiomalonate in THF at 60°C followed by treatment with aqueous sodium hydrogen carbonate and cyclisation as above, yielded the 4-formyl-, 4-acetyl- and 4-methoxycarbonyl-tricyclic ketones 7, 13 and 14 in yields of 31, 35 and 36%, respectively.

An Elegant Synthetic Route to 3-Cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles

2004 ◽  
Vol 59 (1) ◽  
pp. 106-108 ◽  
Author(s):  
Isravel A. Danish ◽  
Karnam J. R. Prasad
Keyword(s):  
Elemental Analysis ◽  
Spectral Methods ◽  
Title Compound ◽  
Sodium Hydride ◽  
Synthetic Route ◽  
Mass Spectral ◽  
Plausible Mechanism

Abstract 2-Benzylidene-1-oxo-1,2,3,4-tetrahydrocarbazoles (1a - e) obtained from the corresponding 1- oxo-1,2,3,4-tetrahydrocarbazoles on reaction with malononitrile in dry benzene with sodium hydride afforded 3-cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles (2a - e) in good yields. A plausible mechanism for the formation of the title compound has been proposed and all the compounds were characterised by IR, NMR, mass spectral methods and elemental analysis.

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