Uracil, 4-Phenyl

Protox-inhibiting herbicides continue to be an area of interest to agrochemical companies, with most effort focused on fine tuning the 5 position of the aromatic ring of N-phenyl uracil to gain both a particular crop/weed/application method as well as a proprietary position. 

Uracil, 5-methoxy-6-methoxymethyl-2-thio-synthesis, 3, 134 Uracil, 1-methyl-aminolysis, 3, 91 synthesis, 3, 110 Uracil, l-methyl-5,6-dihydro-synthesis, 3, 110 Uracil, 6-methyl-3-phenyl-synthesis, 3, 110 Uracil, 3-methyi-2-thio-synthesis, 3, 112 Uracil, 6-methyl-2-thio-oxidation, 3, 94 Uracil, 5-nitro-... 

Several syntheses of annulated uracils of biological value were recently reported. The key reaction was a microwave-assisted one-pot [4 -i- 2] cycloaddition of oxazino[4,5-d]-, pyrano-[2,3-d]-, pyrido[2,3-dj- and pyrimido[4,5-djpyrimidines, in the sohd state [134] and under solvent-free conditions [135]. The synthetic approach was based on the reaction of NJ -di-methyl-5-formylbarbituric acid 208 with maleimide in the sohd state for 5 min under microwave irradiation at 120 °C to give the pyrano[2,3-d]pyrimi-dine derivative 209 in 90% yield (Scheme 76). The reaction of 208 with phenyl isocyanate under microwave irradiation in the absence of solvent... 

P2j Z = 2 DX = 1.43 R = 0.067 for 1269 intensities. The uracil residue is in the anti (63.4°) disposition. The conformation of the D-ribosyl group is 2T3 (176.8°, 37.5°). The orientation about the exocyclic, C-4 -C-5 bond is t (—174.2°). The phenyl and uracil ringsofthe same molecule lie in almost parallel planes, 120 pm apart. The phenyl group is disordered. The uracil ring is sandwiched by the phenyl rings, and vice versa. The 0-1 and N-a atoms of the peptide backbone are hydrogen-bonded to 0-4 and N-3 of atranslationally related uracil to form cyclic dimers. Such interactions serve as models for nucleic acid-protein interactions. [Coordinate errors H(02 ) x should be —1574, instead of —1474 H(Na)2 z should be —145 instead of— 645.]... 

A number of l-aryl-6-aminouracils (LIX Ar = fluoro- or trifluoromethyl-substituted phenyl, X = H, NO or NHj) were found to possess antiviral activity against rhinovims 1059. Among these, l-(OT-trifluoromethylphenyl)-5,6-diamino-uracil (LIX Ar = W-CF3, X = NH2), possesses antibacterial activity against Bacillus subtilis, Staph, aureus zni Mycobacterium smegmatis [410]. 

Pyrimidines can be formed in reactions involving multiple bond formations, and the reactions of this subgroup have a long history <1994HC(52)1>. A recent example is the synthesis of a 6-substituted uracil derivative 740 (Scheme 9), where an a,/3-unsaturated ester 737, A,0-bis(trimethylsilyl)hydroxylamine, phenyl chloroformate, and ammonia supplied the four components of C(4)-C(5)-C(6), N-1, C-2, and N-3, respectively <2000TL4307> ... 

A series of pyrido[2,3-rf pyrimidine-2,4-diones bearing substituents at C-5 and/or C-6 were synthesized using palladium-catalyzed coupling of uracil derivative 417 with vinyl substrates or allyl ethers to give the regioisomeric mixtures of 418/419 and 420/421, respectively. The ratio of the isomeric structures was dependent on the substituent R. In the case of the reaction with -butyl vinyl ether, only the product 419 was obtained. However, the reactions with acrylonitrile, ethyl acrylate, 2-trifluoromethylstyrene, and 3-nitrostyrene afforded only 418. Also, reaction with allyl phenyl ether gave only 420. The key intermediate 417 was prepared by the reaction of 6-amino-l-methyluracil with DMF-DMA (DMA = dimethylacetamide), followed by N-benzylation with benzyl chloride and vinyl iodination with iV-iodosuccinimide (NIS) (Scheme 15) <2001BML611>. 

C, Inhibition of photosynthesis at photosystem II 1,3,5-Triazines Triazinones Uracils Pyridazinone Phenyl carbamates 5... 

Triazine, urea, N-phenyl carbamate, tbiocarbamate, substituted aniline and uracil types Corn, potatoes, carrots GC-MS 0.1 ppm [144,145]... 

In summary, triazine resistance in weeds is most commonly due to a target site alteration that confers a very high level of resistance to. y-triazinc herbicides. Although a Ser264 to Gly mutation in the D1 protein is most common, additional alterations have been identified that confer resistance to triazines and other classes of PS II inhibitors. Enhanced herbicide metabolism plays a major role in conferring resistance in only a few weed biotypes. In these biotypes, the pattern of resistance may be broader, with some cross-resistance to av-trazinones, uracils, heterocyclic ureas and phenyl ureas. The level and pattern of resistance to various herbicides in these biotypes depend, presumably, on the activity and specificity of the enzyme(s) responsible for the enhanced herbicide metabolism. 

Organogermanium sesquioxanes containing uracil or 5-fluorouracil (5-FU) moieties possess antitumor activity against IMC carcinoma in mice118,119. l-[p- Bis(/ -chlorocthyl-amino)phenyl]-2-amino-2-carboxyethylgermanium sesquioxane (LD50 1765 mg kg-1)... 

The base-catalysed reaction of phenyl isocyanate with the morpholino enamines 339 (R1, R2 = H or Ph) gives uracils 340 (equation 138)167. Dithiouracils 341 (n = 1 or 2) are similarly produced from morpholinocyclopentene or -cyclohexene and aroyl isothiocyanates168. Treatment of the dihydrofurans 342 with aryl isocyanates yields derivatives 343 of furo[2,3-d]pyrimidine by way of transient ureas (equation 139)169. 

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