I can't imagine why the Buddha would mention Judaism, even if he knew of it. From a Buddhist perspective, the old Judaism of Moses is a religion based on morals & petty observances, which was not dissimilar to Brahmanism. Based on the Pali scriptures, Brahmanism does not appear as 'polytheistic' as the more recent Hinduism. Although other gods are mentioned, such as Indra or Prajapati, Brahma (the Creator & Father of All) is the primary god; thus close to monotheistic.
While Jews (Isaiah 49) have self-proclaimed themselves 'A Light to the Nations', Buddhism would offer little merit to this Israelite propaganda, written in a tribal scripture (Isaiah) that prophesies doom & destruction to most neighboring nations in the region.
Being merely about morals, Judaism would have been held as similar to many other mundane worldly religions of the Buddha's time; something not offering a path of spiritual liberation. Judaism would have been the kind of socially orientated religion that the homeless ascetics such as the Buddha were running away from.
A quick look at Wikipedia confirms suspicions that some of the more philosophical or eclectic books of the Old Testament are post-Buddhist, such as Ecclesiastes, Job & Jonah. Ecclesiastes is a weak attempt at Buddhist-like wisdom; Jonah speaks of the universal compassion of God (contrary to the previous tribal focus); and, in Job, Satan appears for the 1st time, behaving towards Job similar to Mara towards the Buddha. I would speculate these books, similar to Christianity, were probably influenced by Buddhism.
While Christianity is very close to Buddhism in many of its themes & terminology, such as a 'liberated kingdom not of this world', the very fact that Christianity is not as advanced as Buddhism yet declares itself more spiritually advanced than the ancient worldly moralistic ritualistic Judaism shows how philosophically distant the ancient nationalistic tribal Judaism would have been from Buddhism.