You’re on the right track asking this—these two sentences look similar but aren’t quite the same. Let’s break them down.
1. He answered that for the purpose of his publication he preferred, as between professors and journalists.
— This sentence is grammatical, though the comma is a bit awkward and could be removed or replaced. It seems to mean:
He preferred one group over the other (professors or journalists) for his publication.
Short Tip: This is a formal and slightly old-fashioned structure. “As between X and Y” means “if you had to choose between X and Y.”
2. He answered that for the purpose of his publication he preferred, professors and journalists answered that just for the purpose of their publication they preferred.
— This sentence is not grammatical. It combines two separate statements in a confusing way, and the structure breaks down.
Do both have the same meaning?
No. The first is about his preference, while the second tries to mix in the preferences of both he and professors and journalists, but does so unclearly.
Suggested clearer version of sentence 1:
He said that, for the purpose of his publication, he preferred professors to journalists.