Processes for the preparation of pesticidal compounds

1. A process for the preparation of N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl-N-ethylpropanamide (2a)

which comprises reacting 3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d)

with between 1 and 2 equivalents of 3-chloropropionyl chloride in the presence of an inorganic base.

2. A process according to claim 1 , wherein the base is sodium bicarbonate.

3. A process according to claim 1 in which the 3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d)

is prepared by

(a) alkylating N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c)

with ethyl bromide in the presence of a base to produce N-(3-chloro-1-(pyridin-3-yl )-1H-pyrazol-4-yl)-N-ethylacetamide (1c′)

 and

(b) reacting (1c′) with hydrochloric acid in water at temperatures between 70 ° C. and 90 ° C.