| abstract |
The present invention discloses a compound of formula 3a, which is an intermediate compound for preparing a compound of formula 1, and a method of making the same.n n n <Formula 3a>n n n n n n n n Wherein m is 1, n is 0 or 1,n n n R 1 is a hydrogen atom, C 1 -C 4 -alkyl, C 3 -C 6 -alkenyl or C 3 -C 6 -alkynyl,n n n R 2 is C 1 -C 4 -alkyl, C 3 -C 6 -alkenyl or C 3 -C 6 -alkynyl,n n n X is O, S or NR 4 , where R 4 is a hydrogen atom or C 1 -C 4 -alkyl. |