Publishing a book based on long journal article Recently my article has been accepted for future issue in a prestigious journal published by Jhon Wiley and sons. After accceptance of article I received an email from an other publisher based in Germany that they are interested to publish my work in a form of a chapter of a book. They also offer to get roylity money once the book start selling.  The copy right statement of the journal, where my article is going to appear, states that  the author can publish a pre-print version on public libraries and can self archive on own website. Moreover, it has a 12 months of emborgo period.In given circumstances can I publish my work as a chapter of book as well?
I am not a lawyer, but John Wiley owns the copyright of your current article, and if you just copy larger parts of it into the book chapter, the german publisher will need to obtain permission from John Wiley (that would already be the case for individual figures) and this can well involve transfer of money. That they allow you to publish a pre-print or put it on your personal website is a concession made to you as a person, but not to other (commercial) publishers.

To avoid any of that you would need to re-write (and ideally expand) the article significantly.