[Cleavage of synthetic pentazocine glucuronide with hydrochloric acid]

It has been reported before that pentazocine (I) and pentazocine-glucuronide (II) form an artifact (III) by the addition of water to the double bond in the presence of HCl. This reaction leads to different results concerning the investigation of the rate of hydrolysis of II and the recovery of I. The glucuronide was quantitatively hydrolyzed by 20% HCl, but yielded only 15% of I (about 64% was detected as III). With 5% HCl the rate of hydrolysis only amounted to 40%-43%, whereas I yielded 31% (only 9% was recovered as III). The best III yield was obtained with a HCl concentration of 17.5%.