RC integrator behavior
If your oscilloscope probe input loaded the circuit with 1 Mohm (normal for oscilloscopes, the peak voltage seen would be: -

2.5 volts \$\times\dfrac{1,000,000}{1,000,000 + 200,000} = \$ 2.08 volts

If you have a x10 facility on your probe (10 Mohm input resistance , the voltage would rise to about 2.45 volts.