Thyristor not pulling current away
Conceptually there is nothing wrong with using an SCR to turn off another device such as a transistor. However you must consider the characteristic of both devices to be successful.

First let's consider the transistor circuit you have:







simulate this circuit &ndash; Schematic created using CircuitLab

Consider in this circuit:


You have approximately 24mA of base current flowing into the 2N3904. The BE voltage would be about 0.8V at this base current.
You have approximately 11mA of Collector current flowing to light the LED. 


This is a very unusual configuration where you have more base current flowing than collector current. Even at very low temperatures (where the Hfe drops) you would not consider an Ib/Ic ratio of less than 10:1. So for the load current you show an Ib of 1mA would seem more appropriate. This would mean raising R1 to about 20k Ohm. 

To turn OFF Q1 you need to reduce the Ib current. Your comment that you want 'pull current away' or divert the current is not wrong, but the transistor is NOT simply current driven. You have to consider the BE voltage (it acts much like a forward biased diode). In this sort of circuit you need to hold the BE junction at a voltage that prevents current flowing into the BE junction. 



Since turning OFF means reducing the Ic to close to zero, you need to reduce the voltage on the BE junction to less than 0.6V. At this voltage, there will be very little current flowing into the BE junction. Typically you would do this using another transistor with a VCE(sat) much less than 0.6V,and this would sink the R1 current while starving Q1 BE of current. 

Now let's consider your SCR (I assume you meant a 2N5064 sensitive gate SCR) circuit. One of the characteristics most important in an SCR is the ON state voltage (consider this to be somewhat like the saturation voltage in a transistor).
Dealing with just the SCR circuit:







simulate this circuit

From the above you can see that the SCR is not capable of turning off the transistor, since in your case it is unlikely to pull the V(be) less than 0.78V and at this voltage level there will still be considerable current into the transistor base.

Another characteristic of the SCR is that once turned on it remains on until either the power supply is removed or Ik is reduced beneath the holding current. For the 2N5064 this holding current is about 5mA. So that even if your circuit worked there would be no way to turn OFF the SCR unless you remove the 24V supply. I'm not sure if this was your intent (but I'll assume this was you intent).

There are several ways to fix your circuit detailed below: 







simulate this circuit

I option A, you simply divide the drive voltage to the transistor so it is OFF when the SCR is ON.

In Option B the base voltage required is increased to accommodate the SCR ON state voltage.

In option C since you appear to want only to be able to turn the LED OFF, you could simply use the SCR to lower the voltage available so the LED is OFF. (I'm sure this is not what you actually want to do, but it's there as an option.