Synthesis of 9,10-Dimethyl-1,2-benzanthracene and of a Thiophene Isolog

Sandin, Reuben B.; Fieser, Louis

doi:10.1021/ja01868a055

Cited by 50 publications

(14 citation statements)

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“…The hydrocarbon (250mg.) was converted into 7-iodomethyl-12-methylbenz[a]anthracene by the method of Sandin & Fieser (1940). The crude iodo compound was heated under reflux with potassium acetate (0-5g.)…”

Section: Methodsmentioning

confidence: 99%

METABOLISM OF POLYCYCLIC COMPOUNDS. THE METABOLISM OF 7,12-DIMETHYLBENZ[α]ANTHRACENE BY RAT-LIVER HOMOGENATES

Boyland¹,

Sims²

1965

Biochemical Journal

134

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1. The main products of the metabolism of 7,12-dimethylbenz[a]anthracene by rat-liver homogenates are the isomeric monohydroxymethyl derivatives. The syntheses of these compounds are described. 2. Two phenolic products and two dihydrodihydroxy compounds were formed, but none of these appeared to have been formed by hydroxylation at the ;K region'. There was little evidence for the formation of a glutathione conjugate of the hydrocarbon. 3. The monohydroxymethyl derivatives are products of the hydroxylation of the hydrocarbon in the ascorbic acid-Fe(2+)-oxygen model hydroxylating system.

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Section: Methodsmentioning

confidence: 99%

METABOLISM OF POLYCYCLIC COMPOUNDS. THE METABOLISM OF 7,12-DIMETHYLBENZ[α]ANTHRACENE BY RAT-LIVER HOMOGENATES

Boyland¹,

Sims²

1965

Biochemical Journal

134

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“…7‐IMBA was synthesized according to the method of Sandin and Fieser 11. A Grignard reagent was formed from the reaction of Mg (1 g, 42 mmol) and excess methyl iodide (7 ml) in anhydrous diethyl ether (20 ml).…”

Section: Methodsmentioning

confidence: 99%

Mass spectrometric analysis of 7‐sulfoxymethyl‐12‐methylbenz[a]anthracene and related electrophilic polycyclic aromatic hydrocarbon metabolites

2004

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The Meso-region theory of polycyclic aromatic hydrocarbon (PAH) carcinogenesis predicts that the development of pronounced carcinogenicity depends on the introduction of a good leaving group on alkyl side-chains attached to the exceptionally reactive meso-anthracenic or L-region positions of PAHs. Thus, the first step in carcinogenesis by methylated PAHs such as 7,12-dimethylbenz[a]anthracene (DMBA) would be the hydroxylation of the L-region methyl groups, particularly the 7-methyl group. The second would be the formation of a metabolite, e.g. a sulfate ester, which is expected to be a good leaving group capable of generating a highly reactive benzylic carbocation. 7-Hydroxymethyl-12-methylbenz[a]anthracene (7-HMBA) is a metabolite of DMBA, and sulfation of 7-HMBA to a 7-sulfoxymethyl metabolite (7-SMBA) is a known Phase II metabolic process designed to facilitate excretion, but actually enabling more destructive side-reactions. These side-reactions occur with generation of an electrophilic 7-methylene carbonium ion, and/or by in vivo halide exchange to provide neutral side-products more capable of entering cells, especially those of DMBA target tissues. Electrospray ionization mass spectrometry (MS) enabled us to visualize 7-SMBA as an intact m/z 351 conjugate anion by negative mode, and as a released m/z 255 carbonium ion by positive mode. Upon prolonged refrigeration, 7-SMBA accumulated an m/z 383 photooxide, which appeared capable of re-evolving the starting material as visualized by tandem quadrupole MS, or MS/MS. The 7-SMBA carbonium ion provided interpretable fragments when studied by fragment ion MS/MS, including those representing the loss of up to several protons. Subtle differences in this property were encountered upon perturbing 7-SMBA, either by warming it at 37 degrees C for 2 h or by substituting the initial sulfoxy group with an iodo group. Side-reactions accounting for such proton losses are proposed, and are of interest whether they occur in the mass spectrometer, in solution or both; these proposals include acidity at the 12-methyl position and cyclization between the 12-methyl group and the adjacent C-1 position. It is also suggested that such side-reactions may comprise one route to relieving steric strain arising between the 12-methyl group and the angular benzo ring of 7-SMBA.

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“…With a great surprise, less attention has been devoted to the bromomethylation and iodomethylation of aromatic hydrocarbons, although the iodomethyl and bromomethyl groups are more chemically reactive than chloromethyl group. They were carried out in the same manner as the chloromethylation, that is, with paraformaldehyde/hydrogen bromide/zinc chloride (or hydrobromic acid) [45] and paraformaldehyde/hydroiodic acid/glacial acetic acid [46]. Van der Made and van der Made [47] were able to control the polybromomethylation of mesitylene, durene and prehnitene, upon the bromomethylation with paraformaldehyde/hydrobromic acid/acetic acid; monobromomethylation of the first two aromatics occurred at a temperature of 50 • C and reaction time of 2 h, giving quantitative yields (approx.…”

Section: General View Of the Halomethyaltion Reactionmentioning

confidence: 99%

Towards Halomethylated Benzene-Bearing Monomeric and Polymeric Substrates

Moulay

2011

Designed Monomers and Polymers

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This paper presents the trends in the halomethylation reaction of aromatic hydrocarbons and polymeric analogues. Much interest is devoted to the chloromethylation vis-à-vis other halomethylations, even though the incorporated chloromethyl group is the least chemically reactive among the common halomethyl groups (CH 2 Cl, CH 2 Br, CH 2 I). While bromomethylation stands second behind chloromethylation in terms of chemists' interest, a few cases of iodomethylation are cited, and only one case of fluoromethylation was reported. Various halomethylating systems have been devised, starting from the early one, paraformaldehyde/hydrogen halide, then those involving the in situ formation of halomethyl methyl ether (HalMME), and ending with those giving rise to other intermediate halomethylating species. Halomethylated aromatic polymers, including even the fluoromethylated ones, can be achieved by other means, such as polymerization of halomethyl-containing monomers, halogenation of pendent methyl groups and halogen exchange reaction (halex reaction) within halomethyl groups. Reaction conditions, i.e., solvents, catalysts and promoters, are surveyed. Exploitation of the concomitant Friedel-Crafts alkylation in the course of halomethylation is illustrated by some examples. In addition, the quaternization of halomethylated aromatic polymers (particularly the chloromethylation) is inevitably linked to halomethylation; thus, it is selectively evoked to valorize further the halomethylation reaction.

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Synthesis of 9,10-Dimethyl-1,2-benzanthracene and of a Thiophene Isolog

Cited by 50 publications

References 0 publications

METABOLISM OF POLYCYCLIC COMPOUNDS. THE METABOLISM OF 7,12-DIMETHYLBENZ[α]ANTHRACENE BY RAT-LIVER HOMOGENATES

METABOLISM OF POLYCYCLIC COMPOUNDS. THE METABOLISM OF 7,12-DIMETHYLBENZ[α]ANTHRACENE BY RAT-LIVER HOMOGENATES

Mass spectrometric analysis of 7‐sulfoxymethyl‐12‐methylbenz[a]anthracene and related electrophilic polycyclic aromatic hydrocarbon metabolites

Towards Halomethylated Benzene-Bearing Monomeric and Polymeric Substrates

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