A convenient synthesis of the 2β-azidomethylpenicillin-1,1-dioxides, precursors of the active "YTR" class of β-lactamase inhibitors, is described starting with 6-aminopenicillanic acid (6-APA), which is converted to 6α-bromopenicillanic acid. Oxidation with peracetic acid in the presence of benzophenone hydrazone give benzhydryl 6α-bromopenicillanate-1-oxide in one step and reduction with zinc and acetic acid gave the 6,6-dihydropenicillanate-1-oxide. The unsymmetrical azetidinone disulfide was obtained by heating with 2-mercaptobenzothiazole, and reaction with copper(II) chloride or bromide gave the 2β-halomethylpenams. Reaction with sodium azide in aqueous dimethylformamide gave a mixture of the 2β-azidomethylpenam and the 3β-azidocepham. Oxidation with potassium permanganate gave a mixture of the 2β-azidomethylpenam-1,1-dioxide and the 3β-azidocepham-1,1-dioxide, which was easily separated by fractional crystallization.
一种方便合成2β-
叠氮甲基
青霉素-1,1-二氧化物的方法被描述,该化合物是活性“YTR”类β-内酰胺酶抑制剂的前体,起始物为6-
氨基青霉烯酸(6-APA),它被转化为6α-
溴青霉烯酸。用
过乙酸的氧化反应在苯甲酮
肼酮存在下,一步合成得到苯基6α-
溴青霉烯酸-1-氧化物,随后用
锌和
乙酸还原得到6,6-二氢青霉烯酸-1-氧化物。通过与2-巯基苯
噻唑加热反应获得不对称的
氨基
哌啶二
硫代物,与
铜(II)
氯化物或
溴化物反应得到2β-卤甲基青霉烯。与
水合二甲基甲酰胺中的
叠氮钠反应得到2β-
叠氮甲基青霉烯和3β-
叠氮头孢的混合物。用
高锰酸钾氧化得到2β-
叠氮甲基青霉烯-1,1-二氧化物和3β-
叠氮头孢-1,1-二氧化物的混合物,通过分馏结晶容易分离。