Ammonium Hydroxide → 1,1-dimethylethyl 4-(4-amino-5-bromo-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-1-piperidinecarboxylate

To 1,1-dimethylethyl 4-(5-bromo-4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-1-piperidinecarboxylate (313 mg, 0.753 mmol) was added ammonium hydroxide (2 mL, 51.4 mmol) and 1,4-Dioxane (1 mL) to a 5 mL microwave vial and heated in microwave for 20 min. at 100° C. After total of 35 min. reaction was completed. The reaction was concentrated to give 1,1-dimethylethyl 4-(4-amino-5-bromo-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-1-piperidinecarboxylate (336 mg), which was used without further purification.