- Nitroimidazoles: Part XX- Reactions of 2,4-Dinitroimidazoles with 2-Haloethanols, 3-Chloropropionitrile and Propylene Oxide
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The reaction of 2,4-dinitroimidazole (1) with 2-chloroethanol, 3-chloroethanol, 3-chloropropanol or 3-chloropropionitrile gives 2-chloro-4-nitroimidazole (7) and not 4-chloro-5-nitroimidazole (3) as claimed in earlier literature. 1 and 2-bromoethanol likewise yield 2-bromo-4-nitroimidazole (11). 7 is methylated to isomeric methyl derivatives 8 and 13 and 11 to 12 and 14.In the reaction of 1 with 3-chloropropionitrile, other products 9, 10 and 16 have been isolated. 1 is unaffected by 2-chloropentane. 2-Chloroethanol and 1-methyl-2,4-dinitroimidazole (2) afford 8.HCl formed from hot 2-chloroethanol in the presence of nitroimdazoles seems to be responsible for the displacement of NO2 group at position-2 with chlorine. 1 and propylene oxide yield imidazooxazoline (18) and the dinitro alcohol (19) along with a small amount of the isomer 20. 19 is transformed to imidazooxazoline (21) by excess propylene oxide or piperidine. 7 and propylene oxide afford isomeric alcohols 26 and 27, the latter being readily transformed to 18.Piperidine opens the oxazoline ring 18 to yield 25. 1H NMR and 13C NMR data are used to derive new structures.
- Nagarajan, K.,Shenoy, S. J.
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p. 363 - 368
(2007/10/02)
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- Nitroimidazoles: Part XI - Some Halonitro- and Dinitroimidazoles
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Methylation of 2-chloro-4-nitroimidazole (6), obtained from imidazole in four steps, either with dimethyl sulphate or with diazomethane affords a mixture of 2-chloro-1-methyl-5-nitroimidazole (10) and the 4-nitro-isomer (7).The corresponding dinitro compounds 11 and 8 are formed in the methylation of 2,4-dinitroimidazole (5), 8 being converted to 7 by the action of POCl3.Reaction of 10 with the sodium salt of N-methanesulphonyl-2-imidazolidinone provides the potent amoebicide, 1-methylsulphonyl-3-(1-methyl-5-nitroimidazol-2-yl)-2-imidazolidinone (2).The isomer 14 issynthesised from 7 in low yield.Ethylation of 5 leads to preponderant N-alkylation, providing a mixture of 1-ethyl dinitroimidazoles (9) and (12), but a small amount of N,C-diethyl derivative 15 is also obtained.The formation of 15 from 5 is rationalised.The diiodination product of imidazole is shown to be 4,5-diiodoimidazole (19), nitric acid transforming it to 4-iodo-5-nitroimidazole (20).Methylation of 20 affords a mixture of isomeric 1-methyliodonitro derivatives (21) and (22).The structures of 21 and 22 are established by 13C NMR data as well as by conversion into morpholine derivatives 26 and 24 respectively which also arise from 1-methylchloronitroimidazoles (25) and (23).A mechanism is proposed for the reported conversion of 5 into 4-chloro-5-nitroimidazole (32) in boiling 2-chloroethanol.
- Sudarsanam, V.,Nagarajan, K.,George, T.,Shenoy, S. J.,Iyer, V. V.,Kaulgud, A. P.
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p. 1022 - 1026
(2007/10/02)
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- NITROIMIDAZOLES. PART V. CHLORONITROIMIDAZOLES FROM DINITROIMIDAZOLES. A REINVESTIGATION
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5(4)-Chloro-4(5)-nitroimidazole and 2-chloro-4(5)-nitroimidazole or their N-methyl derivatives have been synthesized in at least two independent routes.In contrast to some former reports it has been established that from 2,4(or 5)-dinitroimidazoles only 2-chloro-4(or 5)-nitroimidazoles are obtained.In 4,5-dinitroimidazoles only a nitro group in the 5-position is replaced by a chlorine atom.Structures of the obtained compounds have been confirmed by analyses of physico-chemical data.
- Suwinski, Jerzy,Salwinska, Ewa,Watras, Jan,Widel, Maria
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p. 1261 - 1272
(2007/10/02)
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