Pyrazolam

Pyrazolam (SH-I-04) is a benzodiazepine derivative originally developed by a team led by Leo Sternbach at Hoffman-La Roche in the 1970s. It has since been "rediscovered" and sold as a designer drug since 2012.

Pyrazolam has structural similarities to alprazolam and bromazepam. Unlike other benzodiazepines, pyrazolam does not appear to undergo metabolism, instead being excreted unchanged in the urine.

United Kingdom
In the UK, pyrazolam has been classified as a Class C drug by section 5 of the May 2017 amendment to The Misuse of Drugs Act 1971 along with several other designer benzodiazepine drugs.

Synthesis

 * Pyrazolam synthesis.svg

The condensation of bromazepam (1) with methylamine and titanium tetrachloride gives the amidine (2). Treatment with nitrous acid gives the nitrosylation product (3). Further reaction with hydrazine gives (4), which is treated with triethyl orthoacetate to complete the synthesis of pyrazolam.