Thevenin Theorem - Open Circuit

Find Voc in this open circuit:
http://i51.tinypic.com/263bz3c.png

-10 + 1200*i1 + 3300*(i1 - i2) - 12 = 0
since i2 = 0 A,
-22 + 4500*i1 = 0
i1 = 22/4500 A = 0.0049 A

Then, for Voc:
3300*(i2 - i1) + Voc + 12 = 0
since i2 = 0 A,
3300*(−22/4500) + Voc + 12 = 0
Voc = 62/15 V = 4.13 V

I just wanted to make sure I did it right. Any help would be appreciated. Thank you in advance :)

You don't need Thevenin, as there is only one loop, I2 = 0

Using the current polarity shown for I1, voltage is 10+12 = 22 volts
Total R is 4.5k
So I1 = 22/4.5k = 4.89 mA

That causes a voltage across R2 of 4.89 x 3.3k = 16.13 volts.
Vab = 16.1–12 = 4.13 volts

.