US 12,264,138 B2
Process for the preparation of microbiocidal oxadiazole derivatives
Thomas James Hoffman, Stein (CH); Regis Jean Georges Mondiere, Stein (CH); Edouard Godineau, Stein (CH); Wolfgang Stutz, Munchwilen (CH); Sujit Kumar Ghorai, Goa (IN); and Anup Jawalekar, Goa (IN)
Assigned to SYNGENTA CROP PROTECTION AG, Basel (CH)
Appl. No. 17/594,469
Filed by SYNGENTA CROP PROTECTION AG, Basel (CH)
PCT Filed Apr. 16, 2020, PCT No. PCT/EP2020/060746
§ 371(c)(1), (2) Date Oct. 18, 2021,
PCT Pub. No. WO2020/212513, PCT Pub. Date Oct. 22, 2020.
Claims priority of application No. 201911015611 (IN), filed on Apr. 18, 2019.
Prior Publication US 2022/0194907 A1, Jun. 23, 2022
Int. Cl. C07D 271/06 (2006.01)
CPC C07D 271/06 (2013.01) 8 Claims
 
1. A process for the preparation of a compound of formula (I):

OG Complex Work Unit Chemistry
wherein
A is A-1

OG Complex Work Unit Chemistry
n is 1;
R1 and R2 are hydrogen
Z is Z1 or Z2:
Z1 is hydrogen, halogen, cyano, —OH, or —SH;
Z2 is —NR3—C(═W)—X
W is O;
X is R5;
R3 is C1-4alkyl, C1-4haloalkyl, C1-4alkoxy, C1-4alkoxyC1-4alkyl or C3-8cycloalkyl;
R5 is C1-4alkyl, C1-4haloalkyl, C2-4alkenyl, C2-6alkynyl, C1-4alkoxy, C1-4haloalkoxy, or C1-4alkoxyC1-4alkyl; or
R5 is C3-8cycloalkyl, or heterocyclyl; wherein said heterocyclyl moiety is a 4- to 6-membered non-aromatic ring which contains 1, 2 or 3 heteroatoms or groups individually selected from O, S, N, NR6, C(═O) and S(═O)2; and wherein any of said cycloalkyl, and heterocyclyl are unsubstituted or substituted by 1 or 2 substituents individually selected from R7;
R6 is hydrogen, C1-4alkyl, C1-4alkoxy, formyl, C1-4alkylcarbonyl, C1-4alkoxycarbonyl, N—C1-4alkylaminocarbonyl, N,N-diC1-4alkylaminocarbonyl, C1-4alkylsulfonyl, N—C1-4alkylaminosulfonyl, or N,N-diC1-4alkylaminosulfonyl; and
R7 is halogen;
said process comprising the step of reacting a compound of formula (II):

OG Complex Work Unit Chemistry
wherein A, n, R1, R2 and Z are as defined for the compound of formula (I), with a compound of formula (III):

OG Complex Work Unit Chemistry
wherein R12 is C1-4alkyl,
wherein the process is carried out in the presence of at least one base;
wherein said base is selected from the group consisting of alkali metal C1-6alkoxylates and alkaline earth metal C1-6alkoxylates, and
said process further comprising the step of isolating the compound of formula (I) using an aqueous acidic medium.