the form of the free amine is not stable over time therefore it is preferred that the compound of formula viib as the free amine is reacted in the next step within a short period of time e g before significant degradation preferably wherein pg 1 is a nitrogen protecting group which may be removed under basic conditions the compound of formula viib is isolated as an acid addition salt according to known methods e g by reacting with a suitable acid such as hcl the compound of formula viib is reacted with a suitably substituted compound of formula viii wherein a u2032 represents an activated form of the a substituent a known compound or compound prepared by known methods in the presence of a tertiary amine base such as dipea tea n methylmorpholine and the like in an aprotic organic solvent such as acetonitrile ethyl acetate mtbe thf and the like preferably acetonitrile or thf preferably under anhydrous conditions preferably the compound of formula viib is added to the compound of formula viii preferably the temperature of the reaction is maintained in the range of about u2212 20 u00b0 c to about 15 u00b0 c more preferably the temperature of the reaction is.