3975 equivalents means in excess.
Grignard reactions of the type R' - C(=O) - N(OR)(R) give ketones of the type R - C(=O) - R'. So the ketone we shall get here is Ph - C(=O) - CH3.
Now again we have a grignard reaction on the ketone (normal alcohol synthesis) to give the product you have mentioned.
The substrate is an oxy-substituted amide, btw.
