Synthesis of trans-tert-butyl-2-aminocyclopentylcarbamate

Abstract

The present invention concerns methods of synthesis of trans-tert-butyl-2-aminocylcopentylcarbamate comprising contacting 6-tosyl-6-azabicyclo[3.1.0]hexane with TMSN 3 and TBAF to produce 2-azido-N-tosylcyclopentananiine; reducing the 2-azido-N-tosylcyclopentanamine to produce 2-amino-N-tosylcyclopentanamine; contacting the 2-amino-N-tosylcyclopentanamine with di-tert/-butyl dicarbonate to produce tert-butyl-2-(tosylamino)cyclopentylcarbamate; and detosylation of tert-butyl O(tosylamino) cyclopentylcarbamate to produce trans-tert-butyl-2-aminocyclopentylcarbamate. The invention also concerns PNAs comprising residues of the monomers of the invention in the backbone and uses of such PNAs. The PNAs of the invention can be used to detect DNAs of infectious agents or to suppress expression of protein associated with cancer.

1 . A compound of the formula 
       
         
           
           
               
               
           
         
       
       having at least 99% enantiomeric purity where Y is a protecting group. 
     
     
         2 . The compound of  claim 1 , wherein Y is t-butyl carbamate. 
     
     
         3 . A compound of the formula: 
       
         
           
           
               
               
           
         
       
     
     
         4 . A method of synthesis of 2-azido-N-tosylcyclopentanamine comprising contacting 6-tosyl-6-azabicyclo[3.1.0]hexane with trimethylsilyl azide (TMSN 3 ) and tetra-n-butylammonium fluoride (TBAF). 
     
     
         5 . The method of  claim 4 , wherein the method is performed at 25-50° C. 
     
     
         6 . The method of  claim 4 , wherein the molar ratio of TMSN 3  to TBAF is 20:1 to 1:1. 
     
     
         7 . The method of  claim 4 , additionally comprising sodium azide. 
     
     
         8 . A method of synthesis of trans-tert-butyl-2-diaminocyclopentylcarbamate comprising contacting 6-tosyl-6-azabicyclo[3.1.0]hexane with TMSN 3  and TBAF to produce 2-azido-N-tosylcyclopentanamine. 
     
     
         9 . The method of  claim 8 , further comprising converting 2-azido-N-tosylcyclopentanamine. to tert-butyl-2-(tosylamino)cyclopentylcarbamate. 
     
     
         10 . The method of  claim 8 , wherein the converting 2-azido-N-tosylcyclopentanamine. to tert-butyl-2-(tosylamino)cyclopentylcarbamate comprises:
 reducing the 2-azido-N-tosylcyclopentanamine to produce 2-amino-N-tosylcyclopentanamine; and   contacting the 2-amino-N-tosylcyclopentanamine with di-tert-butyl dicarbonate to produce tert-butyl-2-(tosylamino)cyclopentylcarbamate.   
     
     
         11 . The method of  claim 9 , further comprising detosylation of tert-butyl-(tosylamino)cyclopentylcarbamate to produce trans-tert-butyl-2-aminocyclopentylcarbamate. 
     
     
         12 . The method of  claim 8 , further comprising:
 reducing the 2-azido-N-tosylcyclopentanamine to produce 2-amino-N-tosylcyclopentanamine;   contacting the 2-amino-N-tosylcyclopentanamine with di-tert-butyl dicarbonate to produce tert-butyl-2-(tosylamino)cyclopentylcarbamate; and   detosylation of tert-butyl-(tosylamino)cyclopentylcarbamate to produce trans-tert-butyl-2-aminocyclopentylcarbamate.   
     
     
         13 . The method of  claim 8 , wherein the molar ratio of TMSN 3  to TBAF is 20:1 to 1:1. 
     
     
         14 . The method of  claim 8 , further comprising sodium azide. 
     
     
         15 . The method of  claim 12 , wherein the reduction of 2-azido-N-tosylcyclopentanamine is obtained by Pd-catalyzed hydrogenation or Staudinger reduction. 
     
     
         16 . The method of  claim 12 , wherein the detosylation of tert-butyl-(tosylamino)cyclopentylcarbamate comprises contacting tert-butyl-(tosylamino)cyclopentylcarbamate with lithium and naphthalene in an aprotic solvent. 
     
     
         17 . The method of  claim 16 , wherein the aprotic solvent is tetrahydrofuran or 1,2-dimethoxyethane. 
     
     
         18 . The method of  claim 16 , wherein the detosylation of tert-butyl-(tosylamino)cyclopentylcarbamate is performed at a temperature between −20° C. and 10° C. 
     
     
         19 . The method of  claim 12 , further comprising contacting the trans-tert-butyl-2-aminocyclopentylcarbamate with a resolving agent to produce a precipitate comprising S,S-tert-butyl-2-aminocyclopentylcarbamate. 
     
     
         20 . The method of  claim 19 , wherein the resolving agent is 10-camphorsulfonic acid. 
     
     
         21 . The method of  claim 19 , further comprising isolating the S,S-tert-butyl-2-aminocyclopentylcarbamate. 
     
     
         22 . A method for producing a peptide nucleic acid containing at least one (S,S,)-trans-cyclopentane or (R,R)-trans-cyclopentane unit in the PNA backbone comprising:
 contacting 6-tosyl-6-azabicyclo[3.1.0]hexane with trimethylsilyl azide (TMSN 3 ) and tetra-n-butylammonium fluoride (TBAF) to produce 2-azido-N-tosylcyclopentanamine;   converting the 2-azido-N-tosylcyclopentanamine to trans-tert-butyl-2-aminocylcopentylcarbamate; and   linking a heterocyclic base moiety to the trans-tert-butyl-2-aminocylcopentylcarbamate and incorporating the resulting compound into the PNA backbone.   
     
     
         23 . The method of  claim 22 , wherein the 2-azido-N-tosylcyclopentanamine to trans-tert-butyl-2-aminocylcopentylcarbamate by a process comprising:
 reducing the 2-azido-N-tosylcyclopentanamine to produce 2-amino-N-tosylcyclopentanamine;   contacting the 2-amino-N-tosylcyclopentanamine with di-tert-butyl dicarbonate to produce tert-butyl-2-(tosylamino)cyclopentylcarbamate; and   detosylation of tert-butyl-(tosylamino)cyclopentylcarbamate to produce trans-tert-butyl-2-aminocyclopentylcarbamate.   
     
     
         24 . A method for detecting a nucleic acid comprising contacting a sample suspected of containing the nucleic acid with a peptide nucleic acid prepared in accordance with  claim 22 . 
     
     
         25 . The method of  claim 24 , wherein the detection is performed visually by an observer. 
     
     
         26 . The method of  claim 25 , wherein the detection is performed by a method comprising:
 contacting a solution comprising a first trans-cyclopentane-containing PNA with a substrate having a second trans-cyclopentane-containing PNA affixed thereto, wherein the first trans-cyclopentane-containing PNA has a reporter molecule attached thereto and the first and second trans-cyclopentane PNAs being complementary to different portions of a target DNA;   contacting DNA with the first and second cyclopentane-containing PNAs;   visually observing the substrate to detect the appearance of color from the reporter molecule.   
     
     
         27 . A kit for detecting a nucleic acid comprising at least one peptide nucleic acid prepared in accordance with  claim 22 . 
     
     
         28 . The kit of  claim 25 , wherein the kit is adapted for detecting an infectious agent, said infectious agent being anthrax, avian flu, severe acute respiratory syndrome (SARS), tuberculosis (TB), human papilloma virus (HPV), or human immunodeficiency virus (HIV). 
     
     
         29 . The kit of  claim 25 , further comprising a biotin-labeled PNA detection probe an avidin-horseradish peroxidase conjugate.