Reaction #83242

Reaction equation

carbamodithioic acid

2-[(methylamino)methyl]-α-phenylbenzenemethanamine dihydrochoride

potassium acetate

potassium chloride

carbon disulfide

→

product

Yield 38.0%

1,2,4,5-Tetrahydro-4-methyl-1-phenyl-3H-2,4-benzodiazepin-3-thione

Yield 38.0%

Solvents

isopropyl alcohol

isopropyl alcohol

Conditions

Workup

1. 1
   Temperaturerefluxed for 30 minutes
2. 2
   TemperatureThe reaction was chilled in ice
3. 3
   Filtrationwas filtered off
4. 4
   workup.ADDITION1.3 mL of of 12N hydrochloric acid was added
5. 5
   TemperatureThe suspension was refluxed for three days
6. 6
   Temperaturecooled
7. 7
   Filtration15.3 g (114%) of the crude benzodiazepin-3-thione was filtered off
8. 8
   OtherA 6-g portion of the crude product was recrystallized from 2-ethoxy ethanol

Procedure

To a suspension of 15 g (50 mmol) of 2-[(methylamino)methyl]-α-phenylbenzenemethanamine dihydrochoride in 100 mL of isopropyl alcohol was added 10 g (100 mmol) of potassium acetate followed by 3.3 mL (55 mmol) of carbon disulfide in 35 mL of isopropyl alcohol. The suspension was stirred at room temperature for one and one-half hours and then refluxed for 30 minutes. The reaction was chilled in ice and the internal salt of the carbamodithioic acid, contaminated with two equivalents of of potassium chloride, was filtered off. The carbamodithioic acid was suspended in 125 mL of 95% ethanol, and 1.3 mL of of 12N hydrochloric acid was added. The suspension was refluxed for three days, cooled, and 15.3 g (114%) of the crude benzodiazepin-3-thione was filtered off. A 6-g portion of the crude product was recrystallized from 2-ethoxy ethanol to yield 2.0 g (38%) of product, mp 208-209.

Source