Manufacture of hydrazinyl compounds useful in the manufacture of pyrazole carboxylic acid and derivatives, hydrazinyl compounds and their use

A process for the manufacture of a compound according to formula (II),

• the process comprising a step of reacting a compound of formula (IV) and a compound of formula (V)
• wherein
• R1 is selected from C1-C4-alkyl groups which may be substituted by one, two or three halogen atoms selected from the group consisting of F, Cl and Br, or by a CF3 group
• R2 is selected from the group consisting of C1-C8-alkyl, aryl, C3-C8 cycloalkyl, aralkyl and heteroaryl, each of which is optionally substituted
• R3 is selected from the group consisting of C1-C12-alkyl, C2-C6 alkenyl, C3-C8 cycloalkyl, aryl, heteroaryl, aralkyl, each of which is optionally substituted;
• or R3 is a nitrogen protecting group
• R4 and R5 independently from each other are selected from the group consisting of H, C1-C12-alkyl, C3-C8 cycloalkyl which optionally contains one or two heteroatoms selected from the group consisting of N, O and S, aryl and heteroaryl, each of which is optionally substituted;
• or R4 and R5 together with the carbon atom to which they are attached form a 4, 5 or 6-membered optionally substituted cycloalkyl, which optionally contains one or two heteroatoms selected from the group consisting of N, O and S, aryl or heteroaryl group, each of which is optionally substituted,
• Y is selected from the group consisting of S, O and NR7,
• R7 and R6 independently are selected from the group consisting of C1-C12-alkyl, C2-C6 alkenyl or C3-C10-cycloalkyl, each of which is optionally substituted,
• or, when Y═NR6, R6 together with R7 and the nitrogen atom to which the two radicals are attached are an optionally substituted 5- to 10-membered heterocyclic radical which, in addition to the nitrogen atom, may contain a further 1, 2 or 3 heteroatoms selected from the group consisting of O, N and S as ring members.

Compound A compound of formula (I),

• wherein
• R1 is selected from C1-C4-alkyl groups which may be substituted by one, two or three halogen atoms selected from the group consisting of F, Cl and Br, or by a CF3 group
• R2 is selected from the group consisting of C1-C8-alkyl, aryl, C3-C8 cycloalkyl, aralkyl and heteroaryl, each of which is optionally substituted,
• R3 is selected from the group consisting of C1-C12-alkyl, C2-C6 alkenyl, C3-C8 cycloalkyl, aryl, heteroaryl, aralkyl, each of which is optionally substituted;
• or R3 is a nitrogen protecting group
• R4 and R5 independently from each other are selected from the group consisting of H, C1-C12-alkyl, C3-C8 cycloalkyl which optionally contains one or two heteroatoms selected from the group consisting of N, O and S, aryl and heteroaryl, each of which is optionally substituted;
• or R4 and R5 together with the carbon atom to which they are attached form a 4, 5 or 6-membered optionally substituted cycloalkyl, which optionally contains one or two heteroatoms selected from the group consisting of N, O and S, aryl or heteroaryl group, each of which is optionally substituted.