Complex sentence: The first rabbi named to lead Kesher Israel on an exclusive basis was Rabbi Jacob Ozer Dubrow, a Chabad "hassid", who was appointed in 1925 and remained with the synagogue until his death in 1944 at the age of 64.
Split into simpler sentences: The first rabbi named to lead Kesher Israel on an exclusive basis was Rabbi Jacob Ozer Dubrow, a Chabad "hassid", who was appointed in 1925. He remained at Kesher Israel until his death in 1944 at the age of 64.