| abstract |
The invention relates to compounds of formula (X), and salts thereof, and their use as intermediates in improved manufacturing processes for the synthesis of pharmaceutical compound (I): X is =O, =N-OH or =N-OC(O)Me; Y is hydrogen, PhS- or p-chlorophenylsulfanyl; Z is hydrogen or -CH2COOR1 wherein R1 is selected from hydrogen, optionally substituted hydrocarbyl and optionally substituted heterocyclyl. |