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G. C. Finger

Publications and source records attributed to G. C. Finger.

17 recordsLinked to original sources
USGS2002

Aromatic fluorine compounds. II. 1,2,4,5-Tetrafluorobenzene and related compounds

The synthesis and properties of 1,2,4,5-tetrafluorobenzene and a group of bromofluoro and chlorofluorobenzenes with a predominating 1,2,4,5-structure are described. Flash point and surface tension data for the fluorinated benzenes and the influence of chlorine substitution upon these values were studied. Under nitration conditions, 1,2,4,5-tetrafluorobenzene will not form a nitro derivative, but will undergo a preferential 1,4-fluorine displacement-oxidation mechanism to give 2,5-difluoro-1,4-benzoquinone. Diazotization reactions on 2-nitro-3,4,6-trifluoroaniline reveal that the nitro group or a fluorine atom in the 4- or 6-position may become labilized, under certain conditions, and undergo replacement.

Journal of the American Chemical Society↗
USGS2002

Aromatic fluorine compounds. III. The fluoromesitylenes and derivatives

Nitration of mesitylene and difluoromesitylene in anhydrous hydrofluoric acid gave near quantitative yields of dinitromesitylene and 2,4-difluoro-6-nitromesitylene, respectively. Difluoro- and trifluoromesitylene were synthesized by the Schiemann reaction in record yields reported for this type of reaction. Various intermediates and derivatives are reported for the fluoromesitylenes. Among the products of exhaustive chlorination of trifluoromesitylene, 2,4,6-tris-(trichloromethyl)-1,-3,5-trifluorobenzene and 2,4,6-trichloro-1,3,5-trifluorobenzene were identified.

Journal of the American Chemical Society↗
USGS2002

Aromatic fluorine compounds. VIII. Plant growth regulators and intermediates

The preparation and properties of 41 fluorophenoxyacetic acids, 4 fluorophenoxypropionic acids, 2 fluorobenzoic acids, several indole derivatives, and a number of miscellaneous compounds are described. Data are given for many intermediates such as new fluorinated phenols, anisoles, anilines and nitrobenzenes. Most of the subject compounds are related to a number of well-known herbicides or plant growth regulators such as 2,4-D, 2,4,5-T and others.

Journal of the American Chemical Society↗
USGS2002

Aromatic fluorine compounds. VI. Displacement of aryl fluorine in diazonium salts

Several chlorofluorobenzenes have been isolated from the Schiemann synthesis of fluorobenzenes. These have been shown to be the products of two side reactions occurring during thermal decomposition of the dry benzenediazonium fluoborate salt containing coprecipitated sodium chloride, an unavoidable contaminant in large preparations involving the use of hydrochloric acid and sodium fluoborate. The major side reaction and its chloro product were unexpected; a unique displacement of fluorine ortho to the diazonium group was observed. Replacement of the diazo group with chlorine was the predicted side reaction which proved to be minor. Conditions causing the side reactions and the isolation and identification of the products are described.

Journal of the American Chemical Society↗
USGS2002

Aromatic fluorine compounds. VII. Replacement of aromatic -Cl and -NO2 groups by -F

Replacement of -Cl by -F in aryl chlorides with potassium fluoride has been extended from 2,4-dinitrochlorobenzene to less activated halides by the use of non-aqueous solvents, especially dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Also replacement of -NO2 by -F in substituted nitrobenzenes was studied in DMF. As a direct result of this study, many aromatic fluorine compounds can now be obtained by a relatively simple synthetic route.

Journal of the American Chemical Society↗
USGS2002

Aromatic fluorine compounds. XI. Replacement of chlorine by fluorine in halopyridines

The α -halogenated pyridines react with potassium fluoride in various solvents to give replacement of the α -halogen by fluorine. A 50% yield of 2-fluoropyridine was obtained from 2-chloropyridine by heating with potassium fluoride in dimethyl sulfone or tetramethylene sulfone for twenty-one days; 2-bromopyridine gave a similar yield with a heating period of only seven days. The α -halogens of the polyhalopyridines undergo the exchange reaction more readily than do the halogens of the α -monohalopyridines. The proposed structures of the fluoropyridines are supported by alternate syntheses and by n.m.r. studies.

Journal of Organic Chemistry↗
USGS2002

Aromatic fluorine compounds. X. The 2,3- and 2,6-difluoropyridines

The preparation of difluoropyridines by the Schiemann reaction was investigated. 2-Amino-6-fluoropyridine (IIIa), necessary for the synthesis of 2,6-difluoropyridine (IVa) by the Schiemann reaction, was conveniently prepared by the Curtius degradation of 6-fluoropicolinic hydrazide (IIa) and by the Hofmann reaction on 6-fluoropicolinamide (IId). Since an α -fluorine on a pyridine nucleus is preferentially replaced by hydrazine when it is either adjacent to or opposite a carbomethoxy group, the hydrazides necessary for the synthesis of 3-amino-2- and 6-fluoropyridine could not be prepared. These amines were prepared from the appropriate 2-fluoropyridinecarboxamide by the Hofmann reaction. The preparation of difluoropyridines was successful with two of the aminofluoropyridines and led to the following new compounds: 2,3-difluoro(IVb) and 2,6-difluoropyridine (IVa).

Journal of Organic Chemistry↗
USGS2002

A combined deamination and nitro reduction method for nitroanilines

The hypophosphorous acid-cuprous oxide deamination method on nitroanilines has been modified so that the nitro compounds which are formed are reduced in turn by cuprous oxide to the corresponding amines. Over-all yields of 55-65% are reported for three halogenated nitroanilines.

Journal of Organic Chemistry↗
USGS1973

Polyphenyl fluorides

Studies related to the chemistry of aromatic fluorine compounds have been carried out at the Illinois State Geological Survey since 1933. In our reference collection we have several compounds that have not previously been described. This communication records data on 18 biphenyl, three terphenyl and some benzene fluorinated derivatives that were obtained as by-products and/or by specific synthesis. ?? 1973.

Journal of Fluorine Chemistry↗
USGS1972

Fluorination of 1,2,3-, 1,2,4-, and 1,3,5-trihalobenzenes with potassium fluoride in dimethyl sulfone

Three trifluorobenzenes were prepared by reaction of the corresponding trichlorobenzenes with potassium fluoride or pottassium fluoride-cesium fluoride mixtures in dimethyl sulfone. Molar yields were 12.8% for 1,2,3-, 8.3% for 1,2,4-, and 56.2% for 1,3,5-. Improved yields of the 1,2,3- (23.9%) and the 1,2,4- (34.0%) trifluorobenzenes were obtained from certain partially fluorinated intermediates. Several chlorofluorobenzene intermediates were obtained in goods yields by careful control of the reaction variables. The instability of the polyfluorobenzenes in the halogen-exchange reaction medium explains, in part, why only limited yields of the polyfluorobenzenes are obtained by using this method.

Journal of Fluorine Chemistry↗