title: Regioselective synthesis of novel N2- and N4-substituted 7-methylpyrazolo[4,5-e][1,2,4]thiadiazines.
abstract: The new compound 7-methylpyrazolo[4,5-e][1,2,4]thiadiazin-3(2H,4H)-one1,1-dioxide (5) was synthesized and its novel mono N2- or N4-substituted derivatives 6 and 7 were prepared by regioselective N-alkylation of 5 with different molar ratios of NaH and alkyl halides. Based on the regioselective alkylation conditions found a facile one-pot synthesis of N2,N4-disubstituted pyrazolo[4,5-e][1,2,4] thiadiazines 8 was developed. The structures of the newly synthesized compounds were confirmed by IR,(1)H-NMR, (13)C-NMR and MS spectral analysis.
authors.affiliation: Institute of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan 250012, PR China. xinyongl@sdu.edu.cn
authors.forename: Xinyong
authors.initials: X
authors.lastname: Liu
authors.forename: Renzhang
authors.initials: R
authors.lastname: Yan
authors.forename: Niangen
authors.initials: N
authors.lastname: Chen
authors.forename: Wenfang
authors.initials: W
authors.lastname: Xu
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Molina
authors.forename: Salvador
authors.initials: S
authors.lastname: Vega
mesh_terms: D000478:Alkylation; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013829:Thiadiazines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D011720:Pyrazoles; D013829:Thiadiazines