Precipitation process of 7-aminocephalosporanic acid (7-ACA)
Patent 6518420 Issued on February 11, 2003. Estimated Expiration Date: November 7, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A process in the isolation of 7-aminocephalosporanic acid (7-ACA) from an alkaline, neutral or slightly acidic medium in the presence of an additive, e.g. selected from the group comprising organic carboxylic acid esters, polymeric glycols, polyacryls, amines and polyamines, melaminformaldehyde resins or amino acids and esters thereof to obtain 7-ACA agglomerates and or rosettes.
European Phamacopoeia, Third Edition, p. 18, 1997.
Academnic Press Dictionary of Science and Technology, Morris, ed, (Academic Press, 1991) pp. 1688, 1690.
Hawley's Condensed Chemical Dictionary, 12th Edition (Van Nostrand Reinhold, 1993), p. 53.
Webster's Third New International Dictionary (Merriam Webster, Inc, 1986) p. 815.
Cieslak, Chemical Abstracts, vol. 90, No. 15, Abstract No. 121587p, p. 646, 1988
Derwent Abstract AN 93-098389 (RO 102 148 A) (1991)
Derwent Abstract AN 94-200170 (WO 94 12504 A and WO 94 12501 A) (1994)
Oberhauser, T. et al., Tetrahedron, vol. 52, No. 22, "On the Stereochemical Purity of (+)-7-Aminocephalosporanic Acid," pp. 7691-7702 (1996