General synonyms:
* In the midst of
* Surrounded by
* In the middle of
* During
* Throughout
* Between
* Among
* In the heart of
* Within
More specific synonyms:
* Amidst (more formal and poetic)
* In the thick of (implies a difficult or challenging situation)
* In the face of (implies a difficult or challenging situation)
* In the wake of (implies a recent event)
The best synonym to use will depend on the context and the desired effect.