Hydrochloric Acid → 1H-Pyrrolo(2,3-b)pyridine

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Reaction Steps

A solution of 2-(tert-butoxycarbonylamino)-3-methylpyridine (Example 2a) (104.1 g, 0.5 mol) in tetrahydrofuran (2.0 liters) was cooled to -1° C. n-Butyllithium (2.5M, 400 ml, 1.0 mol) was added over 45 minutes (temp. ≤+5° C.) and the mixture aged at 0° C. to +3° C. for 1 hour. Dimethylformamide (39.2 ml, 0.51 mol) was added in one portion (temp. -3° C. to 9.9° C.), the mixture was stirred at +6° C. to +18° C. for 1 hour. The yellow suspension was transferred by canula, over 1 hour, into cooled (2.5° C.), vigorously stirred 5.5M hydrochloric acid (500 ml) at such a rate that the temperature was maintained at ≤10° C. The flask and transfer lines were washed through with 2M hydrochloric acid (200 ml) and the stirred mixture was heated at 45°-50° C. for 2 hours.

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