Hydrochloric Acid → 877133-14-7

Temperature

57.5 °C

Water (190 mL) was added to 5-(diethoxymethyl)-3-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (47.6 g, 0.2024 mol, from Step 2), and the mixture was degassed. Then concentrated HCl (73 mL, 0.81 mol, 11.1 M) was added, and the mixture was stirred at 55-60° C. for 24 h. After this, the reaction mixture was evaporated, and the residue was repeatedly (8-10 times) evaporated with THF until the water and HCl were completely removed. The final residue was distilled under vacuum to give the crude title product (bp 46-50° C. at 0.04 mm Hg), containing, according to LC-MS data, 7% of a dimerization side-product. Further purification on a silica gel (ethyl acetate/hexane 1:3) yielded 18.37 g (56.3%) of 3-(difluoromethyl)-1-methyl-1H-1,2,4-triazole-5-carbaldehyde. Satisfactory C,H,N-analysis was obtained. 1H NMR (400 MHz, CDCl3): δ 4.25 (s, 3H), 6.74 (t, J=56 Hz, 1H), 10.01 (s, 1H). LC/MS (API-ES) calcd for C5H5F2N3O: 161.04, found (M+H+): 162.1; (M+18+H+): 180.1 m/z.

1. customthe mixture was degassed
2. customAfter this, the reaction mixture was evaporated
3. customevaporated with THF until the water and HCl
4. customwere completely removed
5. distillationThe final residue was distilled under vacuum
6. customto give the crude title product (bp 46-50° C. at 0.04 mm Hg)
7. additioncontaining
8. customFurther purification on a silica gel (ethyl acetate/hexane 1:3)

ORD record

ord-c4185ae082214ca398aea50b5ac96d39

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08268835B2