None... there is no difference in meaning.

The main difference between these two sentences is the inclusion of the phrase "in a few" in the second sentence: "Within minutes, he was dead." "Within in a few minutes, he was dead." Let's break down the differences: "Within minutes, he was dead." - This sentence means that he died very quickly, possibly within a very short period of time, without specifying an exact duration. It emphasizes the rapidity of his death. "Within in a few minutes, he was dead." - This sentence also conveys a rapid death, but it specifies that it occurred within a few minutes. The inclusion of "in a few" provides a bit more detail about the timeframe, indicating that the death didn't happen instantaneously but still occurred relatively quickly. In summary, both sentences describe a fast death, but the second one adds the detail that it happened within a few minutes, while the first one is more general in terms of the timeframe.

ok. Thank you