3,5-DICHLOROBENZALDEHYDE OXIME synthesis

Yield:93033-57-9 98%

Reaction Conditions:

with hydroxyamino hydrochloride;anhydrous Sodium acetate in ethanol; for 2.5 h;

Steps:

A.1 Intermediate 1: 3,5-Dichlorobenzaldehyde oxime

Intermediate 1: 3,5-Dichlorobenzaldehyde oxime
23.82 g (342.8 mmol) of hydroxylamine hydrochloride were admixed with 80 ml of ethanol.
After addition of 28.12 g (342.8 mmol) of sodium acetate, a solution of 50.00 g (285.7 mmol) of 3,5-dichlorobenzaldehyde in 100 ml ethanol was added dropwise within 30 min, and the mixture was left to stir for 2 h and then left to stand overnight.
The reaction mixture was fully concentrated, then 500 ml of CH₂Cl₂ were added, and the mixture was washed with 400 ml of water.
The water phase was washed once with 100 ml of CH₂Cl₂, and the organic phase was dried over Na₂SO₄, filtered and concentrated.
The residue was used without further purification. Yield: 56.50 g (98%)
¹H NMR (CDCl₃): σ=7.36 (s, 1H, Ar-H), 7.47 (s, 2H, Ar-H), 7.63 (s br, 1H, OH), 8.02 (s, 1H, HC=NOH).

References:

US2015/245616,2015,A1 Location in patent:Paragraph 0179; 0180