Syntheses and Properties of Hexa- and Heptachlorostyrenes with Fully Chlorinated Aromatic Nuclei.

Kolsaker, Per; Storflor, Harry; Brobakke, Kristin; Carlberg, Georg E.; Sterner, Olov; Wickberg, Börje

doi:10.3891/acta.chem.scand.37b-0823

Cited by 7 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The synthesis of hexa-and heptachlorostyrenes with fully chlorinated phenyl ring made the first standards of these groups available (18), while chlorostyrenes with a tetrachlorophenyl nucleus, especially 3, 4, and 6, are still lacking as single substances. Despite the great number of reports on residues of chlorostyrenes in the environment, no systematic study of residue composition has been executed.…”

Section: Introductionmentioning

confidence: 99%

Peak Patterns of Chlorostyrenes in Fish and Fish Oils from the North Atlantic

Coelhan

Reil

Rimkus

et al. 2000

Environ. Sci. Technol.

View full text Add to dashboard Cite

Residues of polychlorinated styrenes have been quantified in fish from different regions of the North Atlantic and in fish oils. One penta-, three hexa-, and six heptachlorostyrenes were identified together with octachlorostyrene. HRGC-EIMS spectra of samples taken from different species and fish oil products show considerable dissimilarities in the peak patterns. In all fish samples except one, (E)-β,2,3,4,5,6-hexachlorostyrene (7) was dominant with concentrations up to 41 ng/g fat followed by octachlorostyrene (11) with concentrations up to 24 ng/g fat. α,2,3,4,5,6-Hexachlorostyrene (2) was found in most fish samples, but in rather low concentrations (0−9.2 ng/g fat), while all other compounds were found in only part of the samples in concentrations up to ca. 12 ng/g fat. In fish oil samples, the ratios of the components were even more divergent with either (E)-β,2,3,4,5,6-hexachlorostyrene (7) or 2,3,4,5,6-pentachlorostyrene (1) or even octachlorostyrene (11) as the main component. Concentrations of (E)-β,2,3,4,5,6-hexachlorostyrene (7) in fish samples correlated with those of octachlorostyrene (11), but in every other respect, no consistent pattern of chlorostyrenes has been found in these samples. Degradation studies indicate that the dominance of (E)-β,2,3,4,5,6-hexachlorostyrene (7) is mainly due to direct input but not to environmental degradation.

show abstract

Section: Introductionmentioning

confidence: 99%

Peak Patterns of Chlorostyrenes in Fish and Fish Oils from the North Atlantic

Coelhan

Reil

Rimkus

et al. 2000

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Significant populations of several solution conformations were indicated. A comparison of 'H NMR data showed that analogous conformations were present in solutions of mycalamide B ( 2) and the structurally similar compounds pederin (4) and onnamide A (6).…”

mentioning

confidence: 95%

“…Preparation of Chiral Amines 4-6. (S)-(-)-l- (2-Chlorophenyl)ethylamine ( 4) and (S)-(-)-l- (2,6-dichlorophenyl)ethylamine (5) were prepared from (S)-(-)-aphenethylamine (3) as described previously.4 (S)-(-)-l- (2,3,4,5,6-pentachlorophenyl)ethylamine (6) hexachlorobenzene with n-BuLi in THF at -30 °C, followed by addition of AC/V-dimethylformamide (-78 --40 °C) afforded pentachlorobenzaldehyde.6 Reaction of the aldehyde with methyl magnesium bromide at 0 °C produced l- (2,3,4,5,6-pentachlorophenyl)ethanol7 in an overall "Reagents: (a) (S)-(-)-a-phenethylamine (3), 180 °C, neat, 2 h; (b) (S)-(-)-a-phenethylamine (3), (S)-(-)-l-(2-chlorophenyl)ethylamine ( 4), (S)-(-)-l-(2,6-dichlorophenyl)ethylamine (5), or (S)-(-)-l- (2,3,4,5,6-pentachlorophenyl)ethylamine (6), benzene or neat, 25 °C or 80 °C; (c) l,l'-carbonyldiimidazole, THF-ra-Bu20, 90 °C, 120 "C, or 135 °C; (d) LiEt3BH, THF, -78 °C; (e) SnCl4, CH2C12, -22 "C, allyltrimethylsilane. yield of 55%.…”

mentioning

confidence: 99%

“…The amine was then converted to its mandelate salt with (R)-(-)-mandelic acid. Three recrystallizations from ethyl acetate-methanol followed by liberation of the free base with 1 N NaOH afforded (S)-(-)-l- (2,3,4,5,6-pentachlorophenyl)ethylamine (6) of 98% ee. The enantiomeric excess and configuration of the chiral amine were determined by conversion of 6 to the corresponding amide with (R)-(+)-MPTA chloride.10 Comparison of the !H NMR spectrum of the amide derived from (S)-6 with that of the amide derived from (R)-(+)l- (2,3,4,5,6-pentachlorophenyl)ethylamine revealed the following chemical shifts.…”

mentioning

confidence: 99%

“…(13b):33 (14b) 2,6-Cl2Ph (2c) 88 2 (13c):98 (14c) "Combined yield of both diastereomers after purification by flash chromatography. 6 Determined by capillary GC analysis (DB-5, 30 m) and/or HPLC (ISCO 5 pm silica, 254 nm). sation decreased dramatically upon progressive substitution of the aromatic ring of a-phenethylamine with chlorine atoms.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Stereoselective nucleophilic additions to the carbon-nitrogen double bond. 3. Chiral acyliminium ions

Polniaszek¹,

Belmont²,

Alvarez³

1990

J. Org. Chem.

View full text Add to dashboard Cite

mL). Na2C03 was added until the solution pH was about 5. Ti02 (anatase, MCB, 3.0 g) was added. While being stirred in a quartz tube, the mixture was irradiated with a 500-W Xenon lamp for 10 h. The mixture was centrifuged to isolate the solid, which was then washed 4 times with 25 mL of H20. The platinized (grey) Ti02 was dried in an oven (132 °C) overnight. Lower loading levels were attained by a modification of the same procedure.Photolysis Procedure. Ti02 (5 mg) was added to a solution of diacid (0.01 M) in 50 mL of aqueous HN03 (pH = 1), which was agitated in an ultrasonic bath for 15 min to form a suspension. Magnetically stirred reaction mixtures in Pyrex tubes were irradiated in a Rayonet photochemical reactor (temperature ca. 52

show abstract