1. $-3 \cdot(-7) \cdot(-15) \cdot(-5)$

Step 1 ：Multiply the given numbers: \(-3 \cdot(-7) \cdot(-15) \cdot(-5)\)

Step 2 ：Since there are four negative numbers, the result will be positive: \(3 \cdot 7 \cdot 15 \cdot 5\)

Step 3 ：Calculate the result: \(3 \cdot 7 \cdot 15 \cdot 5 = 1575\)

Step 4 ：\(\boxed{1575}\)