Step 2: Synthesis of 4-amino-N,N-dimethylbenzamide (Intermediate 74)
Tert-butyl 4-(dimethylcarbamoyl)phenylcarbamate (Int.73, 1.11 g, 4.21 mmol) was dissolved in ethyl acetate (20 ml) to which ethyl acetate solution (18 ml, 76 mmol) of 4M HCl was added. The reaction mixture was stirred at room temperature for 5 hours. After completion of the reaction, the pH was adjusted to 6-7 with saturated NaHCO3 solution.The aqueous phase was extracted with ethyl acetate (3 x 20 ml). The organic phases were combined, dried over anhydrous Na2SO4 and concentrated under reduced pressure to give 615 mg of the title product (Int.74).