5-Bromo-6-methyl-3 uracil

The uracils with herbicidal activity do not necessarily contain 5-halo substituents. 3-Cyclohexyl-5-methyluracil [354] (XLIV), l,3-di-isopropyl-6-methyl-uracil [352] (XLV) and 3-s-butyl-5-thiocyanato-6-methyluracil [353] (XLVI), for example, are cited as having this type of activity. 3-Butyl-6-methyluracil (XLlllc) possesses interesting selective activities. For instance, this pyrimidine kills many annual weed species without damage to peas and peanuts, even when applied at twice the concentration needed to kill the weeds [346]. On the other hand, the related 5-bromo derivatives, such as (XLlIlb), are useful as industrial herbicides where it is desirable to kill all plants [346]. 

Wyler et al. [146a-c] have focused on the hetero Diels-Alder reaction of a,/)-unsaturated-acyl cyanides such as 2-140 with ethyl vinyl ether, N-methylated uracil and l-bromo-2-ethoxyethenes 2-141. In the latter case the dihydropyran... 

Katritzky AR, Waring AJ (1962) Thutomeric azines. Part I. The tautomerism of 1-methyl-uracil and 5-bromo-l-methyl-uracil. J Chem Soc 1540-1544... 

L. Pichat, J. Godbillon, and M. Herbert, Lithiation par le n-butyllithium de bromo-5 uracile nucleosides silylds. Preparation de methyl ( C-5) et methyl ( -6) uridine, de desoxy-2 -ethyl (l C-5) uridine et desoxy-2 -ethyl ( C-ti) uridine, B H. Soc. Chim. Fr. 2712 (1973). 

The Suzuki coupling of 44 was utilized to prepare 5-substituted uracils as potential antiviral agents [21, 22]. Adduct 45, derived from 44 and 2-bromo-3-methylthiophene, was transformed to the corresponding uracil 46 via acidic hydrolysis. Conveniently, reversal of the coupling partners also resulted in formation of adduct 45, assembled from the Suzuki coupling of 5-bromo-2,4-di-f-butoxypyrimidine (43) and 3-methyl-2-thiopheneboronic acid. 

Boyarchuk and Volkenshtein354,355 have studied the IR spectra of the crystals of 5-bromo-l-methyl-, 5-bromo-3-methyluracil, and 1-methylthymine and discussed the effect of the electronegative substituents in the pyrimidine ring on the potential energy curve of dimeric hydrogen-bonded complexes of uracil derivatives. Features of the IR spectrum of 5-bromo-l-methyluracil crystal suggested that the stability of the lactim form 28 increases owing to the influence of the substituents. 

Under conditions of the Hilbert-Johnson reaction, the 2,4-dialkoxypyrimidines (29) can furnish the following by-products uracil,13 1-alkyluracil,3-7 1,3-dialkyluracil,19 4-alkoxy-2(lIZ)-pyri-midinone,7 and l-alkyl-4-alkoxy-2(lH)-pyrimidinone.7,20 Thus, for example, 5-chloro-, 5-bromo-, and 5-iodouracil were isolated32- 33 as by-products in the Hilbert-Johnson reaction (in acetonitrile at 20°) of the corresponding 5-halo-2,4-dimethoxypyrimidines and 3,5-di-O-p-toluyl-2-deoxy-D-ribofuranosyl chloride. The formation of 1,3-dimethyluracil and 1,3,5-trimethyluracil as by-products has been observed quite recently19 when the reaction of 2,3,5-tri-O-benzoyl-D-ribofuranosyl chloride with 2,4-dimethoxypyrimidine and 5-methyl-2,4-dimethoxypyrimidine, respectively, was performed in toluene at 70°. 

SYNS BOREA BROMAZIL 5-BROMO-3-sec-BUTYU6-METHYLURACIL 5-BROMO-6-METHYL-3-(l-METHYLPROPYL)-2,4(lH,3H)-PYRIMIDINEDIONE 5-BROMO-6-METHYL-3-(l-METHYLPROPYL)URACIL 3-sek.BUTYL-5-BROM-6-METHYLURACIL (GERMAN) CYNOGAN DU PONT HERBICIDE 976 EEREX GRANULAR WEED KILLER EEREX WATER SOLUBLE CONCENTRATE WEED KILLER HERBICIDE 976 HYVAR HYVAREX HYVARX ... 

Bromacil. 5 Bromo-6-methyl-3-(] - met hy(propyl)-2,4(IH,3H)-pyrimidittedione 5-bromo-3- ec lnityl-6-methyt-uracil 5-bromo-6-methyl-3-(1 -methylpropyl)uracil du Pont herbicide 976 Hyvarl Uragon Urox B. N. o, ... 

Synonyms/Trade Names 5-Bromo-3-sec-butyl-6-methyluracil, 5-Bromo-6-methyl-3-(1-methylpropyl)uracil ... 

Synonyms 5-Bromo-3-s-butyl-6-methyl-1 H-pyrimidine-2,4-dione 5-Bromo-3-s-butyl-6-methyluracil 5-Bromo-6-methyl-3-(1-methylpropyl)-2,4(1 H,3H)-pyrimidinedione 5-Bromo-6-methyl-3-(1-methylpropyl) uracil Empiricai C9Hi BrN202... 

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