5-fluoro-2- thiazole

The usual order found with halogenonitrobenzenes is F > Cl Br I, the order of Cl and Br being variable, just as in heteroaromatic reactivity. The position of fluorine is of interest the available data indicate that it is usually the same as for nitrobenzene derivatives. Thus, in acid hydrolysis the order F > Cl for 2-halogeno-quinolines can be deduced beyond doubt since the fluoro derivative appears to react in the non-protonated form and the chloro derivative to resist hydrolytic attack even in the protonated form under appropriate conditions (Section II,D, l,d). Furthermore, in the benzo-thiazole ring, fluorine is displaced by the CHgO reagent at a rate 10 times that for chlorine. ... 

Logothetis [62] describes the use of triazine accelerators in the vulcanization of nitrile and fluoro elastomers. The triazine is more effective than the thiazole accelerators and produces highly reversion-resistant vulcanizates. 

The most important applications of the in situ photochemical fluorodediazoniation start from heterocyclic amines for which the diazonium tetrafluoroborates are impossible to isolate. In this way, fluorinated imidazoles,123-253,254-257 261 benzimidazoles,262 pyrazoles,254-256,262 indazoles,158 thiazoles,259 and triazoles259-262 have been prepared (Table 4). Some of these are the precursors of biologically active compounds such as fluoro-substituted histidines or histamines,123,253-257,258 or 5-fluoro-l/ -D-ribofuranosylimidazole-4-carboxamide.261... 

Propanoic Acide 2-Benzoylamino-2-(4-methoxy-benzyl)-3,3.3-tri-fluoro- E10b2, 180 (subst. 5-Oxo — 4.5-112 1,3-thiazole/HCl)... 

Carboxy-l-cyclopropyl-6.8-di-fluoro-4-oxo-7-( 1,3-thiazol-2-ylsulfanyl)- E10b2, 447 (F - S-Het)... 

Dichloro-3-[2-ethoxycarbonyl-3-(thiazol-2-ylamino)acryloyl]-5-fluoropyri-dine (13) gave ethyl 7-chloro-6-fluoro-4-oxo-l-(thiazol-2-yl)-l,4-dihydro-l,8-naphthyridine-3-carboxylate (14) (Bu OK/dioxane 63%).143... 

Aminopyrrolidin-1 -yl)-6-fluoro-4-oxo-1 -(thiazol-2-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid (13, R = OH) gave the corresponding 3-carboxamide (13, R = NH2) via the unisolated acid chloride (13, R = Cl) (ClC02Et, Et3N then NH3/EtOH 54%).352... 

Reaction of 9-fluoro-8-isothiocyanato- and 8-iso(thio)cyanato-3,5, 6,7-tetrahydro-2//-pyrido[l,2,3-de]-l,4-benzoxazines with 2-amino-4,4-dimethylpyrroline, then with Br2, and with ethyl pipecolinate yielded 8-(6, 6-dimethyl-3,5,7,7-tetrahydropyrrolo[2,l-c][l,2,4]thiadiazol-3-ylidenamino)-9-fluoro and 8-(l,3-dioxo and l-oxo-3-thioxoperhydroimidazo[l,5-a]-pyridin-2-yl) derivatives, respectively (89EUP406993). Treatment of 9-fluoro-8-(2-hydroxymethylpiperidinothiocarbonylamino)-3,5,6,7-tetrahydro-2//-pyrido[l,2,3-de]-l,4-benzoxazine with HC1 gas in EtOH gave the 8-(perhy-dropyrrolo[l,2-c]thiazol-3-ylidenamino) derivative. 

Fluoro-7-methyl-lH-indazol-3-yl)-5-pyridin-3-yl-thiazol-4-yl] -(4-pyridin-2-ylmethyl-piperazin-1 -yl)-methanone 1 H TC r N r N o... 

Satoh A, Nagatomi Y, Hirata Y et al (2009) Discovery and in vitro and in vivo profiles of 4-fluoro-N-[4-[6-(isopropylamino)pyrimidin-4-yl]-l, 3-thiazol-2-yl]-N-methy lbenzamide as novel class of an orally active metabotropic glutamate receptor 1 (mGluRl) antagonist. Bioorg Med Chem Lett 19 5464-5468... 

The easy ring-opening quality of hexafluoro-1,2-epoxypropane in the presence of a nucleophile has been used to accomplish the synthesis of imidazo[2,l-ft]thiazol-3(2//)-one. Thus, the sodium salt of 4,5-diphenylimidazolyl-2-thione (16, R1 = R2 = Ph) reacts with hexafluoro-1,2-epoxypropane in acetonitrile to furnish 5,6-diphenyl-2-fluoro-2-triflu-oromethylimidazol2,l-b]thiazol-3(2W)-one (18f) in a one-step synthesis (78BCJ3091). 

C. glutamicum 2-thiazole-3-Ala ttiazole-Ala 2-fluoro-His purine and pyrimidine analogues 15 ... 

Reddy, A.C.S. Rao, P.S. Venkataratnam, R. V. Fluoro organics facile syntheses of novel 2-or 4-trifluoromethyl-l//-arylo-l,5-diazepines, oxazepines, thiazepines, 2-(l,l,l-trifluor-oacetonyl)imidazoles, oxazoles and thiazoles. Tetrahedron 1997, 53(16), 5847-5854. 

Bixafen is another pyrazole carboxamide recently developed by Bayer CropScience. These active ingredients illustrate the fluoro-substituted pyrazole, thiazole, and pyrrole carboxamides as left part of the molecules that are being developed by several companies. 

Fluoro-2-(4-methoxyphenyl)benzo[d]thiazole (2a) White solid, mp. 132.9-133.7 °C reaction time 12 h yield 91%... 

However, Selectfluor was not as effective as AccufluoitS) (64) for the fluorination of 2,4-diarylthiazoles since it gave admixture of the 5-chlorolhiazole that was difficult to remove [77]. Fluorination of this diaryl system with 64 occurred selectively at the 5-position of the thiazole however, as the reaction could not be driven to completion, the yields were low to moderate (19-43 %) [77]. Other N-F reagents were also examined to improve the effectiveness of fluorination reaction and eliminate the formation of the chlorinated byproducts. Compared to 63, only a small amount of fluorination occurred when diarylthiazole was reacted under similar conditions with N,N-difluoro-2,2-bipyridinium bis(tetrafluoroborate) (65) or with l-fluoro-2,6-dichloropyridinium triflate (66) [77]. 

---