Abstract: This invention provides a method for preparing compounds having the structure [Formula (I)] wherein L is [Formula (A)] or [Formula (B)] in which R1 is hydrogen or optionally substituted alkyl, n is zero or 1 and m is 1; wherein R is H, halogen, optionally substituted C1-6alkyl or C1-6alkoxy; wherein Z is a bond, O or S; wherein p is an integer from 1 to 5; wherein Q is a bond provided that Z is not a bond when p is 1; or Q is O, S or —C(O)NR6— in which R6 is hydrogen, optionally substituted alkyl or cycloalkyl; or Q is —NR6—, —NR5C(O)NH— or —NR5C(O)O— in which R5 is hydrogen, alkyl or aralkyl provided that p is not 1; wherein W is cycloalkyl, aryl or heterocyclyl; or W and R6 form a 9- to 10-membered bicyclic ring, which may be optionally substituted or may contain oxygen, nitrogen or sulfur.