Synspilum don't pair off as easily as some other cichlids. Its generally better to start with a group of 6 or so until you get a pair, rather than trying your luck with just 2.
Also, I note that you have goldfish in your tank with the synspilum. Goldfish are coldwater fish, cichlids are tropical. It might be that the temp is too cool for the synspilum to breed, or even thrive. What is the temp inside your tank? I'm pretty sure that the ideal breeding temp for your synspilum will be too high for the goldfish.