Hydrochloric Acid → 3-tert-butyl-1,4-dihydro-1,2,4-triazol-5-one

Semicarbazide hydrochloride (25.0 g, 224 mmol) was dissolved in water (200 mL). NaHCO3 (40.0 g, 476 mmol) was slowly added to the solution over 30 min at RT followed by the addition of trimethylacetyl chloride (30.0 g, 249 mmol). The mixture was stirred at RT for 12 h. Solids were collected by filtration, washed with cold water, and dried in vacuo. A solution of NaOH (20.0 g, 500 mmol) in water (200 mL) was added. The mixture was stirred at 100° C. for 2 h, cooled with an ice-bath, and neutralized by the drop-wise addition of concentrated HCl. The solids were collected by filtration, washed with water, and dried in vacuo to afford 3-(tert-butyl)-1H-1,2,4-triazol-5(4H)-one (19.6 g, 61.9%) as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 11.26 (s, 1H), 11.04 (s, 1H), 1.16 (s, 9H); MS (ESI) m/z: 142.1 (M+H+).

1. filtrationSolids were collected by filtration
2. washwashed with cold water
3. customdried in vacuo
4. stirringThe mixture was stirred at 100° C. for 2 h
5. temperaturecooled with an ice-bath
6. filtrationThe solids were collected by filtration
7. washwashed with water
8. customdried in vacuo

ORD record

ord-be665c8e334d4e4ca5c4ea7f7e9174de

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09193719B2