Kaiser ninhydrin

After the reaction times given in Scheme 38, the respective couplings were quantitative according to chloranil and the Kaiser ninhydrin test and/or HPLC of small cleavage. The peak area of the crude Fmoc-deprotected dodecapeptide was 90% (HPLC k=214nm). The pure cyclic peptide was obtained in an overall yield of 31%. Cyclosporin O was synthesized by a similar procedure.129 ... 

Primary aliphatic Kaiser (ninhydrin)/ c trinitrobenzenesulfonic acid (TNBSA)/... 

Qualitative color tests are frequently used to follow reactions to assure completion. The Kaiser ninhydrin test is the best known of these [15], An improved method for the detection of secondary amines has been reported [16], The Fmoc method for assuring complete deprotection of an amine is in wide use [13],... 

Linker attachment An amino-functionalized polystyrene or PEG-polystyrene resin may be used as starting material. First, 5-(4-formyl-3,5-dimethoxyphe-noxy)valeric acid (PALdehyde) [122] (4equiv.) and HATU [123] (4equiv.) were dissolved in DMF, DIEA (8 equiv.) was then added, and, after 1 min of pre-activation, this solution was added to the resin (1 equiv.). Coupling was allowed to proceed at 25 °C for 2 h, after which the Kaiser ninhydrin test [81] was negative. 

Reagents for the Kaiser Ninhydrin test were purchased from Aldrich and Fisher and used without further purification phenol, ninhydrin, KCN, pyridine. 

Confirm the presence of the sulfonamide on solid support with the standard Kaiser ninhydrin test (39) outlined below ... 

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