Patent ID: 6512111
Filing Date: 2003-01-28
Classification: C07K

Abstract:
A process for the preparation of a compound of the formula wherein R is selected from the group consisting of hydrogen, and alkyl, aryl and aralkyl up to 18 carbon atoms and the amine function can be free or protected comprising cyclizing a compound of the formula wherein R has the above meaning and the amine function can be free or protected in a basic medium and in the presence:of a derivative of phosphonic acid of the formula P(â€”Z)(X1)(X2)(X3)â€ƒâ€ƒP1 wherein Z is a sulfur or oxygen, X1 is halogen, X2 and X3 are individually selected from the group consisting of halogen, alkoxy, of 1 to 6 carbon atoms, aryloxy of 6 to 12 carbon atoms and arylalkoxy of 7 to 15 carbon atoms,or of a trimer of the formula