We don't have any other pin to pin compatible product to replace MAX1687. MAX1687 is still in production as of 9/27/2018. It is mostly compatible with MAX1688, except the difference of the function of pin 3 in SO package and pin 5 in TSSOP package. MAX1687 controls peak battery current while MAX1688 features a more advanced, adaptive constant recharge-time algorithm that maximizes battery life.
The MAX1688 typical application circuit is as shown in the figure below: