It is not safe to use fasting to lose such a huge amount of weight purposefully. It is possible you could lose that amount of weight dry fasting. I have done so and dry fast that amount of time regularly. But I have done many extended Water Fasts and dozens of dry fasts previously. And I would not plan a long dry fast without preparing on raw foods for an extended period beforehand, and even then I would be prepared to drink- or eat- if necessary at any point. To have such a huge weight loss goal in such a short period of time rather than letting the fast take it's own course makes the chances you could ignore danger signals far more likely than would usually be the case.
I don't reccommend fasting for short term weight loss at all. Curezone has forums dedicated to weight loss I believe and you would be better off consulting them.