| Title:  Benzo[a]pyrene CAS Registry Number:  50-32-8 Additional Names:  3,4-Benzpyrene Molecular Formula:  C20H12 Molecular Weight:  252.31 Percent Composition:  C 95.21%, H 4.79% Literature References:  Formerly called 1,2-benzpyrene.  Occurs in coal tar, q.v.  Isoln by fractionation:  Cook et al., J. Chem. Soc. 1933, 395; by adsorption and fluorimetric determn:  Hieger, Am. J. Cancer 29, 705 (1937); Winterstein et al., Z. Physiol. Chem. 230, 158, 169 (1934); Naturwissenschaften 22, 237 (1934).  Synthesis from pyrene and succinic anhydride:  Cook, Hewett, J. Chem. Soc. 1933, 398; Fieser, Fieser, J. Am. Chem. Soc. 57, 782 (1935); Winterstein et al., Ber. 68, 1079 (1935); Fieser et al., J. Am. Chem. Soc. 57, 1509 (1935).  Absorption spectrum:  Mayneord, Roe, Proc. Roy. Soc. London A152, 299 (1935).  Review:  Clar, Polycyclic Hydrocarbons Vol. 1 & 2 (Academic Press, New York, 1964).  Review of carcinogenicity studies:  IARC Monographs 3, 91-136 (1973).  Inhibition of the mutagenicity of the ultimate carcinogenic metabolite of benzo[a]pyrene by ellagic acid:  A. W. Wood et al., Proc. Natl. Acad. Sci. USA 79, 5513 (1982).  Study of the reaction between this metabolite (benzo[a]pyrene-7,8-diol 9,10-epoxide) and ellagic acid:  J. M. Sayer et al., J. Am. Chem. Soc. 104, 5562 (1982).  Review:  D. H. Phillips, Nature 303, 468-472 (1983).  Review of toxicology and human exposure:  Toxicological Profile for Polycyclic Aromatic Hydrocarbons (PB95-264370, 1995) 487 pp. Properties:  Yellowish plates, needles from benzene + methanol, mp 179-179.3°.  Crystals may be monoclinic or orthorhombic.  bp10 310-312°.  Violet fluorescence of dil benzene solns:  Hieger, loc. cit.  Soluble in benzene, toluene, xylene; sparingly sol in alc, methanol.  Practically insol in water. Melting point:  mp 179-179.3° Boiling point:  bp10 310-312° CAUTION:  This substance is reasonably anticipated to be a human carcinogen:  Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-220.  |