Programming :: Imagemagick With For Loop On The Commandline Does Not Work

I have images in jpg format

Code:

CIMG0100.jpg
...
...
CIMG0131.jpg

I used imagemagick to convert the files to gif with the following command

Code:

for i in {100..131}; do convert CIMG0$i.jpg CIMG0$i.gif; done # works

This worked like expected, but when afterwards I wanted to scale the images

Code:

for i in {100..131}; do convert -scale 25% CIMG00$i.gif CIMG00$i_scaled.gif; done # works not it seems the system is working for about half a minute, but I get no output. The single command

Code:

convert -scale 25% CIMG100.gif CIMG100_scaled.gif # works

works as expected and gives me a scaled image. What does the convert command do in the second case? is the for-loop wrong?