5-Benzyloxyindole → 5-(Benzyloxy)-1H-indol-1-amine

Participants

Reaction Steps

A solution of 5.3 kg (5.2 kg corrected for 97% purity) of hydroxylamine-O-sulfonic acid (HOSA) in 19.1 kg of N-methylpyrrolidinone (NMP), is prepared and chilled to 0–5° C. A second solution is prepared from 10.6 kg (10.0 kg corrected for 95% purity) of potassium tert-butoxide and 19.3 kg of NMP. An amination vessel is charged with 5.0 kg (4.7 kg corrected for 94% purity) of 5-benzyloxyindole, 15.5 kg of NMP and an initial charge of 0.4 kg of the potassium tert-butoxide/NMP solution. The HOSA/NMP solution and the remaining potassium tert-butoxide/NMP solution are then simultaneously and proportionally metered into the amination vessel over a period of 166 minutes while maintaining a reaction temperature of 14–29° C. to yield a solution containing 4.3 kg (86.0% yield) of 5-benzyloxy-1H-indol-1-amine as determined by external standard HPLC assay. After adding 105 L water, and cooling to 0–5° C., the mixture is filtered. The filtered solid is partitioned with 63 L n-butyl acetate and 8.5 L water, then filtered. The organic phase is concentrated under reduced pressure to give a solid which contains 3.9 kg (77.4% yield) of 5-benzyloxy-1H-indol-1-amine as determined by external standard HPLC assay.

Provenance & Evidence