ChemInform Abstract: SYNTHESIS AND CHEMICAL REACTIONS OF ACETYLAMINO DERIVATIVES OF ADAMANTANE

Synthesis of Rigid Multivalent Scaffolds Based on Adamantane

“…The N -acetyl group in amide 6 can be removed by acidic hydrolysis of the acetamide in refluxing aqueous HCl to give the free amine 7 as its hydrochloride salt. Loss of the amine function under acidic conditions and substitution with chlorine has been reported for alkyl-substituted aminoadamantanes in the literature . However, for the conversion of amide 6 to amine 7 we were not able to detect any substitution of the amine function by chlorine during acidic hydrolysis.…”

“…Loss of the amine function under acidic conditions and substitution with chlorine has been reported for alkyl-substituted aminoadamantanes in the literature. 15 However, for the conversion of amide 6 to amine 7 we were not able to detect any substitution of the amine function by chlorine during acidic hydrolysis. Amino acid 7 is well soluble in water at acidic pH, and all impurifications were thus removed by washing the acidic aqueous reaction mixture with ethyl acetate.…”

“…A second protocol for a one-step conversion of adamantane derivatives to N-acetamides via a bromine free amidation 15 failed to give tetrafunctionalized adamantane 6, and only a complex mixture of reaction products was isolated.…”

γ‐Aminoadamantanecarboxylic Acids Through Direct C–H Bond Amidations

“…Moreover, bromine has to be distilled prior to use to avoid overfunctionalization due to traces of Lewis acids; [21][22][23] excess bromine has to be redistilled or disposed after the reaction. In view of these limitations, we set out to advance a Ritter-type protocol [24,25] that allows for direct C-H bond amidation of various adamantane derivatives without a prior halogenation step (Table 1). In order to activate the adamantane tertiary C-H bonds, we decided to use nitrating acid (HNO 3 /H 2 SO 4 ) of various compositions, because under these conditions the key single electron oxidizer NO 2 + is generated in situ.…”