Bromazolam

Bromazolam is classified as a novel benzodiazepine which was first synthesised in 1976, but was never marketed. It has subsequently been sold as a designer drug, first being definitively identified by the EMCDDA in Sweden in 2016. It is the bromo instead of chloro analogue of alprazolam, and has similar sedative and anxiolytic effects. Bromazolam is structurally similar to traditional benzodiazepines, including alprazolam (replacing the chlorine with a bromine) and bromazepam (addition of triazole ring). Alprazolam and bromazepam are Schedule IV substances in the United States; bromazolam is not explicitly scheduled.

8-Bromo-1-methyl-6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine is used to study the antianxiety activity, antidepressant and psychotropics for central nervous system.

Bromazolam(8bromo) is a synthetic cannabinoid that has been used as an alternative to marijuana. It has been shown to induce psychosis in animals and humans and is associated with high rates of depression. 8bromo was found to be effective against cancer cells in vitro and in vivo, but not against bacteria or fungi. In humans, 8bromo increased the levels of liver enzymes. This agent has also been shown to have antiinflammatory properties that are mediated by prostaglandin synthesis inhibition.

The synthesis of Bromazolam is as follows：
A solution of 1 (1 g, 3.07 mmol of 7-bromo-5-phenyl-1,4-benzodiazepine-2-one) in dry THF (20 mL) was cooled in an ice-water bath and a 60% dispersion of sodium hydride (152.2 mg) was added in one portion. After 20 minutes, di-4-morpholinylphosphinic chloride (943.9 mg, 4.76 mmol) was added at 0° C. and this was stirred for 30 minutes and allowed to warm to room temperature (Ning, R Y., et al., (1976) J Org Chem 41: 2724-2727). The mixture was stirred for 1.5 hours. To this mixture was then added a solution of acetylhydrazide (521.9 mg, 7.14 mmol) in dry butanol (5 mL) and stirring was continued at room temperature for 10 min. The solvents were evaporated and the residue was dissolved in butanol (10 mL) and heated to reflux for 5 hours. Butanol was removed under reduced pressure and the residue was partitioned between CH2Cl2 (50 mL) and water (50 mL). The water layer was extracted by CH2Cl2 (3×30 mL). The combined organic layer was washed by brine (30 mL). The organic layer was dried (Na2SO4) and the solvent was removed under vacuum. The residue was purified by flash chromatography (silica gel) to provide pure 8 [539.5 mg (40% yield)] as a white solid.