I have submitted a research paper in mathematics to a journal and also uploaded it to Arxiv. Another paper I have written is an extension of this yet unpublished paper. So in the second paper, I have to mention or cite the first. Since the previous paper is yet not published, I have only one option: cite it from the Arxiv link. But I am thinking that citing a paper that is in Arxiv (submitted to a journal and yet not published), will be less appealing to reviewers.
So the question: Is it a good idea to cite my own unpublished paper to another paper, extension of the previous paper ?