- Friedel-Crafts Acylation with 2-Isocyanatobenzoyl Chlorides: The Structure of the Intermediate Complex
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The intermediate complex obtained in the Friedel-Crafts acylation of benzene with 2-isocyanatobenzoyl chloride (1a) reacts with methanol or ethanol in the presence of ether affording 4-alkoxy-4-phenyl-1,4-dihydro-3,1-benzoxazin-2(1H)-ones, whereas with anilines, the corresponding anils of 2-aminobenzophenone are obtained.In the presence of triethylamine, the complex reacts with aniline and 2-aminobenzophenone affording 4-hydroxy-4-phenyl-3-substituted 3,4-dihydroquinazolin-2(1H)-ones whereas, with alkyl anthranilates, the new 11b-phenyl-7,11b-dihydroquinazolinobenzoxazine-6,13-diones are obtained.Similar products are also obtained from 5-chloro-2-isocyanatobenzoyl chloride.The intermediate complex has been shown to exist exclusively in the cyclic form in both acidic and basic media.
- Acharya, Baman Prasad,Rao, Y. Ramachandra
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p. 1001 - 1035
(2007/10/02)
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- Synthesis of Unsymmetrically Substituted 6,12-Diaryldibenzodiazocines and Their Precursor Schiff Bases
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A new route for the preparation of some unsymmetrically substituted 6,12-diaryldibenzodiazocines 5 and their precursor Schiff bases 4 from 2-isocyanatobenzoyl chloride and its 5-chloro derivative are described.
- Acharya, Baman P.,Ramachandra Rao, Y.
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p. 324 - 326
(2007/10/02)
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- Friedel-Crafts Acylation of Some Aromatic Compounds with 2-Isocyanatobenzoyl Chloride
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Friedel-Crafts acylation of benzene, toluene, anisole and chlorobenzene with 2-isocyanatobenzoyl chloride (1) afford either 2-aminobenzophenones (2) or 4,4-diaryl-1,2-dihydro-3,1-benzoxazin-2(4H)-ones (3) as major products depending on reaction temperature and/or substrate reactivity.Other minor products isolated are 3-aryl-1,2,3,4-tetrahydroquinazoline-2,4-diones (4), 6,12-diaryldibenzodiazocines (6) and 2-aminophenyl-α,α-diarylmethanols (7).The formation of 2 and 3 has been shown to take place via a common intermediate complex to which the cyclic 4-aryl-3,1-benzoxazinonium ion structure (12) has been assigned on the basis of its rection with methanol and 2-aminobenzophenone.While the formation of 6 occurs through the intermediate complex (12), 4-aryliminoquinazolin-2-ones (5) are formed most probably from the 1-AlCl3 complex.
- Misra, B. K.,Rao, Y. R.,Mahapatra, S. N.
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p. 1132 - 1138
(2007/10/02)
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