Semisynthetic Penicillins. II. Structure-Activity Studies on the 2-Biphenylyl Side Chain¹

Reagents with a Crystalline Coat

“…Here, the reaction was significantly slower (Figure S19), probably owing to slow release of the reagent. Interestingly, with [BzCl] TDA , a cleaner reaction occurred than when the benzoylated penicillin was synthesized with free BzCl in the same solvent (Figure d). Both in this reaction mixture and in the one involving aminophenol, the solution darkened quickly when the reaction was performed with free BzCl.…”

Reagents with a Crystalline Coat

“…Here,t he reaction was significantly slower ( Figure S19), probably owing to slow release of the reagent. Interestingly,with [BzCl] TDA ,acleaner reaction occurred than when the benzoylated penicillin [19] was synthesized with free BzCl in the same solvent (Figure 3d). Both in this reaction mixture and in the one involving aminophenol, the solution darkened quickly when the reaction was performed with free BzCl.…”

Direct diazo-transfer reaction on β-lactam: Synthesis and preliminary biological activities of 6-triazolylpenicillanic acids

“…We selected a subset of terminal alkynes whose closely related carboxylic acid analogs have been shown to support the antimicrobial activities of β-lactams. [38][39][40] Alkynes such as 7, 10h, 10i, and 10k that we could not obtain from commercial sources were synthesized from the corresponding carboxylic acid, through the intermediacy of aldehyde, using the Bestmann-Ohira reagent. [41][42][43] Hydroxyl alkyne 10f and 10l were obtained by a direct Grignard reaction of ethynylmagnesium bromide with the appropriate aldehydes.…”