Facile synthesis of mono-6-amino-6-deoxy-alpha-, beta-, gamma-cyclodextrin hydrochlorides for molecular recognition, chiral separation and drug delivery.
We describe a protocol for the synthesis of mono-6-amino-6-deoxy-cyclodextrin hydrochloride (CD-NH3Cl), applicable to alpha-, beta- and gamma-cyclodextrin. These structurally simplest, highly water-soluble cationic cyclodextrins can be widely used in molecular recognition, chiral separation and drug delivery studies. Starting from commercially available chemicals, CD-NH3Cl is synthesized in four steps: (i) selective tosylation of cyclodextrin by the use of p-toluenesulfonyl chloride to afford mono-6-(p-toluenesulfonyl)-6-deoxy-cyclodextrin (Ts-CD); (ii) azide substitution of Ts-CD with sodium azide to afford mono-6-azido-6-deoxy-cyclodextrin (CD-N3); (iii) reduction of CD-N3 with triphenylphospine followed by hydrolysis to prepare mono-6-amino-6-deoxy-cyclodextrin (CD-NH2); and (iv) treatment of CD-NH2 with hydrochloric acid to afford the titled CD-NH3Cl with good yield. The overall protocol requires approximately 2 weeks.
Tang
Weihua
W
Department of Chemistry, National University of Singapore, Singapore 117543, Singapore. weihuatang@alumi.nus.edu.sg
Ng
Siu-Choon
SC
D003505:Cyclodextrins / Q000138:chemical synthesis*; D016503:Drug Delivery Systems; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry
D003505:Cyclodextrins; D011725:Pyridines