Patent GB-631269-A (GB)
Title: Improvements in or relating to pyrazole compounds
IPC: C07D405/12
Filed: 1947-05-01
Abstract: 5 - Acyloxypyrazole amidoaldehydes and acetals of the formula <FORM:0631269/IV (b)/1> where Y is a carbonyl (-CO-) or sulphonyl (-SO2-) group (RY-being an acyl radical), R1 is a divalent organic radical linked by "hydrocarbon" carbon atoms, Z and Z1 are hydrogen, amidoaldehyde or amidoacetal groups at least one of Z and Z1 being amidoaldehyde or acetal, are prepared by treating a 5-acyloxypyrazole containing a carboxylic or sulphonic acid halide group in at least one of the 1- and 3-positions with an aminoaldehyde or an acetal thereof in which the acetal group is derived from an alkanol of 1-4 carbon atoms or a 1 : 2-or 1 : 3-dihydroxyalkane of 2-4 carbon atoms, in the presence of an acid binding agent.  A preferred class of compound is <FORM:0631269/IV (b)/2> where R2 is hydrocarbon, B is as R1 but need not be the same.  In all cases the acyl group RY- includes RCO- and RSO2-.  Other preferred compounds are <FORM:0631269/IV (b)/3> where A1 is hydrocarbon attached to the N-atom through an aromatic nucleus, B1 is phenylene, and R3 is alkyl of 1-3 carbon atoms, alkoxy of 1 or 2 carbon atoms, phenyl, and methyl- or ethyl-phenyl.  In all cases the hydrocarbon nuclei may be substituted by, e.g. methoxy, alkyl, aryl, halogen and nitro groups. The reaction is carried out at -10 DEG  to +40 DEG  C. (preferably -5 DEG  to +5 DEG  C.) in a solvent, e.g. dioxane, acetone, alcohol, or benzene, or mixtures of such solvents with water, in the presence of acid-binding agents, e.g. carbonates, sodium formate or acetate, or tertiary amines such as pyridine.  Acetal groups may be hydrolysed to the free aldehyde with acid.  Many starting materials are specified, both pyrazolyl acid chlorides, e.g. 1-(4-chloroformylmethoxyphenyl)-3-naphthyl-5-pyrazolyl chlorobenzoate, 1 - (21 - benzthiazolyl) - 3 - (p - chloroformylphenyl)-5-pyrazolyl benzoate, and 1-(21-methoxy - 51 - pyrazolyl methyl carbonate, and aminoaldehydes and acetals, e.g. 1-amino-2 : 2 - diethoxyethane and 2 - chloro - 4 -amino-benzaldehyde dimethyl acetal.  In the examples, (1) m-[p-(5-ethylcarbonato-3-methyl-1-pyrazolyl) -benzamido]-benzaldehyde ethylene glycol acetal is prepared by reacting m-amino-benzaldehyde ethylene glycol acetal with 1-(41-chloroformylphenyl) - 3 - methyl - 5 - pyrazolyl ethyl carbonate in the presence of aqueous dioxan and potassium carbonate and the acetal group may then be hydrolysed; (2) m-[p-(5-benzoxy-3-methyl-1-pyrazolyl)-benzene-sulphonamido] - benzaldehyde ethylene glycol acetal is similarly prepared and hydrolysed; (3) m-[p-(5-benzoxy - 3 - methyl - 1 - pyrazolyl)-phenoxyacetamido]-benzaldehyde is obtained from m - aminobenzaldehyde - ethylene - glycol acetal and 1-(41-chloroformylmethoxyphenyl)-3-methyl-5-pyrazolyl benzoate; (4) 1-(41-carboxyphenyl)-3-methyl-5-pyrazolone is treated with acetic anhydride and sodium acetate to give 1-(41-carboxyphenyl)-3-methyl-5-pyrazolyl acetate, which is treated with thionyl chloride to give 1-(41-chloroformylphenyl)-3-methyl-5-pyrazolyl acetate, which is then reacted with m-aminobenzaldehyde dimethyl acetal; (5) m-[p-(5-benzoxy-3-methyl-1-pyrazolyl)-benzamido] benzaldehyde is obtained by reacting 1-(41-chloroformylphenyl)-3-methyl-5-pyrazolyl benzoate with m-aminobenzaldehyde ethylene-glycol acetal and hydrolysing the product; and (6) m - [p - (5 - ethylcarbonato - 1 - phenyl - 3 - pyrazolyl)-benzamido] benzaldehyde ethylene glycol acetal is obtained from m-aminobenzaldehyde ethylene glycol acetal and 1-phenyl-3-(41-chloroformylphenyl)-5-pyrazolyl ethyl carbonate, and the product may then be hydrolysed to give the free aldehyde. Specification 629,482 is referred to.ALSO:5-Acyloxypyrazole amidoaldehydes and acetals of the formula <FORM:0631269/IV (c)/1> (where Y is -CO- or -SO2-, RY- being acyl, R1 is a divalent radical or two such radicals joined by groups such as -O-, -S-, -CO-, &c., Z and Z1 are hydrogen, amidoaldehyde or amidoacetal groups, only one of which can be hydrogen) couple readily with diazo compounds.