I don’t deny the anti-Semitic aspect to some of Marx’s thought. However, he does actually believe that Jews should be emancipated despite the fact he has some unsavory things to say about Judaism. His writings on the topic are a bit complicated.
I recommend the following academic article:
Avineri, Shlomo. “Marx and Jewish Emancipation.” Journal of the History of Ideas, vol. 25, no. 3, 1964, pp. 445–50. Available on JSTOR