Synthesis of Lidocaine percent yield question

Feb 2013
Calculate the overall percent yield of the synthesis to produce crude lidocaine.

My total weight of crude lidocaine is 0.627g

The limiting reagent in this reaction is diethylamine I believe.

I used 7.5 mL of diethylamine (MW=73.1g/mol ; density= .71g/ml)

7.5mL*(.71g/mL)= 5.33g*(1mol/73.1g) = .073 mol

.073 mol * (197.4 g/mol Lidocaine) = 14.4 grams

Im not sure if this is right, or if I need more steps. Any help appreciated.