Fluorobenzoates

Although fluorotoluenes have yielded the corresponding fluorobenzoates, these reactions are merely biotransformations since the fluorobenzoates are terminal metabolites  

The metabolism of fluorobenzoates has been examined over many years. Early studies using Nocardia erythropoUs (Cain et al. 1968) and Pseudomonas fluorescens (Hughes 1965) showed that although the rates of whole-cell oxidation of fluorobenzoates were less than for benzoate, they were comparable to, and greater than for, the chlorinated analogs. As for their chlorinated analogs, both dioxygenation and hydrolytic pathways may be involved, and studies have revealed that the different pathways depended on the positions of the fluorine substituents. 

FIGURE 9.29 Transformation of 2-halogenated benzoates to catechol by concomitant decarboxylation and dehalogenation. (From Neilson, A.H. and Allard, A.-S., The Handbook of Environmental Chemistry, Vol. 3R, Springer Verlag, 2002, pp. 1-74. With permission.) 

2- halobenzoate-l,2-dioxygenase is also different from the three-component enzyme in Pseudomonas aeruginosa strain 142 (Romanov and Hausinger 1994), which contains a [2Fe-2S] ferredoxin, and is active toward 2,5-dichlorobenzoate though less toward 2,6-, 3,4-, and 3,5-dichlorobenzoate. 

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Alkaline hydrolysis of pentafluorobenzoic acid, the probable intermediate in the alkaline hydrolysis of perfluorotoluene, gives a high yield of p-hydroxytetra fluorobenzoic acid [9, 10 (equation 10)... 

Polymorphic forms of I and II of 3- 2-[4-(6-fluorobenzo[r/ isoxazol-3-yl)-3,6-dihydro-2//-pyridin-l-yl]ethyl -2-methyl-6,7,8,9-tetrahydro-4//-pyrido [1,2-n]pyrimidin-4-one was characterized by IR spectroscopy (99MIP1). 

Two polymorphic forms of 3- 2-[4-(6-fluorobenzisoxazol-3-yl)-l,2,3,6-tetrahydropyridin-l-yl]ethyl -2-methyl-6,7,8,9-tetrahydro-4//-pyrido[l,2-n] pyrimidin-4-one (137 R = H) were prepared (99MIP1). Racemic 9-hydroxy-2-methyl-3- 2-[4-(6-fluorobenzo[r/ isoxazol-3-yl)-l,2,3,6-tetrahydro-l-pyridyl] ethyl -6,7,8,9-tetrahydro-4//-pyrido[l, 2-n]pyrimidin-4-one was resolved into its (R)- and (5)-isomers (OOMIPIO). 

Poor yields of azepines are formed with 6-carboxy, 6-chloro, and 3,5-dichloro groups, and methyl 2-azido-5-nitrobenzoate fails to undergo ring expansion.74 Surprisingly, the azido-fluorobenzoates, which undergo successful ring expansion in diethylamine solution, fail to yield 2-methoxy-37/-azepines on photolysis in methanol.188... 

CfiH3N02S 874-84-0) see Temocapril 2-nitro 5-fluorobenzoic acid (C7H4FNO4 320-98-9) see Flumazenil... 

Acetylene, derivatives 359, 361, 362 Acetylsalicylic acid 308 ACFB = 2-amino-5-chloro-2 -fluorobenzo-phenone 227 Aconitic acid 249... 

A strain of Rhodococcus opacus isolated by enrichment with chlorobenzene was able to grow at the expense of a wide range of halogenated compounds. These included 1,3- and 1,4-dichlorobenzene, 1,3- and 1,4-dibromobenzene, 2-, 3-, and 4-fluorophenol, 2-, 3-, and 4-chlorophenol, 4-nitrophenol, 3- and 4-fluorobenzoate, and 3-chlorobenzoate (Zaitsev et al. 1995). 

Fluoride during the conversion of 3-fluorotoluene into 3-methylcatechol (Renganathan 1989), and of both fluoride and carboxyl during the degradation of 2-fluorobenzoate (Engesser et al. 1980). 

Engesser KH, E Schmidt, H-J Knackmuss (1980) Adaptation of Alcaligenes eutrophus B9 and Pseudomonas sp. B13 to 2-fluorobenzoate as growth substrate. Appl Environ Microbiol 39 68-73. 

Engesser KH, G Auling, J Busse, H-J Knackmuss (1990) 3-Fluorobenzoate enriched bacterial strain FLB 300 degrades benzoate and all three isomeric monofluorobenzoates. Arch Microbiol 153 193-199. 

Schreiber A, M Hellwig, E Dorn, W Reineke, H-J Knackmuss (1980) Critical reactions in fluorobenzoic acid degradation by Pseudomonas sp. B13 Appl Environ Microbiol 39 58-67. 

Horvath RS, P Flathman (1976) Co-metabolism of fluorobenzoates by natural microbial populations. Appl Environ Microbiol 31 889-891. 

A two-component 2-halobenzoate 1,2-dioxygenase has been purified from Pseudomonas cepacia strain 2CBS that is able to metabolize 2-fluorobenzoate, 2-chlorobenzoate, 2-bromobenzoate, and 2-iodobenzoate to catechol by concomitant decarboxylation and loss of halide (Fetzner et al. 1992). The inducible 2-halobenzoate 1,2-dioxygenase consisted of... 

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