Ethoxyacetyl chloride → 3-Ethoxymethyl-4-methyl-1,2,4-triazoline-5-thione

Ethoxyacetyl chloride (57 g.) was added slowly to a stirred solution of 4-methylthiosemicarbazide (53.5 g.) in dry pyridine (500 ml.) at 0°-5°. The mixture was allowed to attain room temperature and stirring was continued for 18 hours. Following concentration under reduced pressure the residue was treated with a solution of sodium (21.4 g.) in ethanol (500 ml.) and the mixture was heated under reflux for 24 hours. Following concentration and acidification with hydrochloric acid a solid was obtained. After partial concentration the solid was collected and recrystallised from ethyl acetate to give 3-ethoxymethyl-4-methyl-1,2,4-triazoline-5-thione (53 g.), m.p. 137°-138°. The thione (44 g.) was desulphurised by slow addition to a solution prepared from nitric acid (75 ml.) water (150 ml.) and sodium nitrite (1.5 g.) at 15°-20°. Following subsequent basification with sodium carbonate and concentration the residue was extracted with ethanol-ether 1:1 and distilled to afford 3-ethoxymethyl-4-methyl-1,2,4-triazole (30 g.) b.p. 154°-156°/0.05 mm. The above compound (15 g.) dissolved in 48% aqueous hydrobromic acid (150 ml.) was heated under reflux for 24 hours and concentrated to dryness to give 3-hydroxymethyl-4-methyl-1,2,4-triazole.

1. customto attain room temperature
2. concentrationconcentration under reduced pressure the residue
3. additionwas treated with a solution of sodium (21.4 g.) in ethanol (500 ml.)
4. temperaturethe mixture was heated
5. temperatureunder reflux for 24 hours
6. concentrationconcentration and acidification with hydrochloric acid a solid
7. customwas obtained
8. concentrationAfter partial concentration the solid
9. customwas collected
10. customrecrystallised from ethyl acetate

ORD record

ord-73520023266c44ed8386d25a1bafd9c8

Source dataset

uspto-grants-1979_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04154844