507262-32-0

Upstream product

• 98-54-4 para-tert-butylphenol 
• 31603-95-9 1-(tert-butoxy)-4-(tert-butyl)benzene 

Downstream Products

• 371-41-5 4-Fluorophenol 
• 16222-41-6 tert-butyl 4-fluorophenyl ether 

Relevant academic research and scientific papers

Fluorine Radiolabelling Process

The invention relates to a process for producing a process for producing an 18F-labelled compound, the process comprising treating a compound of formula (I) wherein EDG is an electron-donating group selected from —OH, —OR4, —NHR5 and —NR55R5; R1, R2, X1 and X2 are as defined herein; and R3 is selected from H, X3 and X4, wherein X3 is a monodentate cleavable surrogate group, and X4 is a bidentate cleavable surrogate group which is bonded (a) to said X1 or X2 and (b) to the ring carbon atom para to EDG; with [18F]fluoride in the presence of an oxidant, thereby producing, when R3 in the compound of formula (I) is H, an 18F-labelled compound of formula (II), wherein EDG is as defined above and R1, R2, X1 and X2 are as defined herein; or thereby producing, when R3 in the compound of formula (I) is said monodentate cleavable surrogate group X3, a compound of formula (IIa), wherein EDG′ is O, NR5, —NR55R5 or [OR4]+, and wherein R4, R5, R55, R1, R2, X1, X2 and X3 are as defined herein; or thereby producing, when R3 in the compound of formula (I) is said bidentate cleavable surrogate group X4, a compound of formula (IIc) or a compound of formula (IId), wherein EDG′ is O, NR5, —NR55R5 or [OR4]+, and wherein R4, R5, R55, R1, R2, X1, X2 and X4 are as defined herein

Fluorination of 4-alkyl-substituted phenols and aromatic ethers with fluoroxy and N-F reagents: Cesium fluoroxysulfate and N-fluoro-1,4-diazonia- bicyclo[2.2.2]octane dication salts case Dedicated to Prof. Dr. Boris ?emva in honor to his great contribution to fluorine chemistry.

4-Alkyl-substituted phenols and aromatic ethers were comparatively fluorinated with electrophilic fluorinating reagents such as cesium fluoroxysulfate (CFS), Selectfluor F-TEDA-BF4, and Accufluor NFTh in MeCN or MeOH. Reactions resulted in the formation of three types of products: 2-fluoro-4-alkyl-substituted corresponding compounds (5) as a result of ortho fluorination process, 4-alkyl-4-fluoro-cyclohexa-2,5- dienone compounds (6), resulting after an addition-elimination process, and 4-fluorosubstituted corresponding compounds (7) derived from ipso attack and release of the 4-alkyl group. The distribution of products depends on the bulkiness of alkyl groups at both positions and reaction media. The reaction in methanol proved more selective toward the formation of 2-fluoro derivatives. Tyramin and l-tyrozine were transformed with NFTh reagent in methanol to their fluorophenyl-substituted derivatives in good yield.

FLUORINE RADIOLABELLING PROCESS

The invention relates to a process for producing a process for producing an 18F-labelled compound, the process comprising treating a compound of formula (I): wherein EDG is an electron-donating group selected from -OH, -OR4, -NHR5 and -NR55R5; R1, R2, X1 and X2 are as defined herein; and R3 is selected from H, X3 and X4, wherein X3 is a monodentate cleavable surrogate group, and X4 is a bidentate cleavable surrogate group which is bonded (a) to said X or X and (b) to the ring carbon atom para to EDG; with [18F]fluoride in the presence of an oxidant, thereby producing, when R3 in the compound of formula (I) is H, an 18F-labelled compound of formula (II), wherein EDG is as defined above and R1, R2, X1 and X2 are as defined herein; or thereby producing, when R3 in the compound of formula (I) is said monodentate cleavable surrogate group X4, a compound of formula (Ilc), wherein EDG' is O, NR5, -NR55R5 or [OR4]+, and wherein R4, R5, R55, R1, R2, X1, X2 and X3 are as defined herein; or thereby producing, when R3 in the compound of formula (I) is said bidentate cleavable surrogate group X4, a compound of formula (IIc) or a compound of formula (IId), wherein EDG' is O, NR5, -NR55R5 or [OR4]+, and wherein R4, R5, R55, R1, R2, X1, X2 and X4 are as defined herein.

The role of F-N reagent and reaction conditions on fluoro functionalisation of substituted phenols

The effect of steric interactions on the regioselectivity of fluorination of para alkyl substituted phenols was investigated and the strong effect of size of the alkyl substituent, the structure of the F-N reagent and the solvent on the site of fluorination was established. The course of reaction obeyed a second order rate equation, while the fluorination process required higher ΔH≠ activation than oxidation or oxidative demethylation. Solvent polarity variations had a small effect on the rate of functionalisation, while an excellent Hammett correlation with ρ+=-2.3 was determined.

Synthesis of 4-fluorophenols from 4-tert-butylphenols and fluoride sources under oxidative conditions

4-tert-Butylphenols can be easily transformed into 4-fluorophenols, provided that no coordinating moiety is present in 2-position, in a two step procedure under mild and safe conditions. The first step leads to 4-tert-butyl-4-fluorocyclohexa-2,5-dien-1-ones through an oxidative fluorination with [bis(trifluoroacetoxy)iodo]benzene and triethylamine tris(hydrofluoride), and is followed by an acid catalyzed aromatization with loss of isobutene. When extended to 4-tert-butylacetanilide, this method delivers 4-fluoroacetanilide in a single step but in a modest yield.