title: Synthesis and in vitro antitumor activity of thiophene analogues of 5-chloro-5,8-dideazafolic acid and 2-methyl-2-desamino-5-chloro-5,8-dideazafolic acid.
abstract: N-[5-[N-(2-Amino-5-chloro-3,4-dihydro-4-oxoquinazolin-6-yl)methylamino]-2-thenoyl]-L-glutamic acid (6) and N-[5-[N-(5-chloro-3,4-dihydro-2-methyl-4-oxoquinazolin-6-yl)methylamino]-2-thenoyl]-L-glutamic acid (7), the first reported thiophene analogues of 5-chloro-5,8-dideazafolic acid, were synthesized and tested as inhibitors of tumor cell growth in culture. 4-Chloro-5-methylisatin (10) was converted stepwise to methyl 2-amino-5-methyl-6-chlorobenzoate (22) and 2-amino-5-chloro-3,4-dihydro-6-methyl-4-oxoquinazoline (19). Pivaloylation of the 2-amino group, followed by NBS bromination, condensation with di-tert-butyl N-(5-amino-2-thenoyl)-L-glutamate (28), and stepwise cleavage of the protecting groups with ammonia and TFA yielded. Treatment of 9 with acetic anhydride afforded 2,6-dimethyl-5-chlorobenz[1,3-d]oxazin-4-one (31), which on reaction with ammonia, NaOH was converted to 2,6-dimethyl-5-chloro-3,4-dihydroquinazolin-4-one (33). Bromination of, followed by condensation with and ester cleavage with TFA, yielded. The IC(50) of and against CCRF-CEM human leukemic lymphoblasts was 1.8+/-0.1 and 2.1+/-0.8 microM, respectively.
authors.affiliation: Dana-Farber Cancer Institute and the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Forsch
authors.forename: Joel E
authors.initials: JE
authors.lastname: Wright
authors.forename: Andre
authors.initials: A
authors.lastname: Rosowsky
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D005492:Folic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D005493:Folic Acid Antagonists / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D007945:Leukemia, Lymphoid / Q000473:pathology; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship; D013876:Thiophenes / Q000737:chemistry*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D005493:Folic Acid Antagonists; D013876:Thiophenes; D005492:Folic Acid