Processes to produce certain 2-(pyridine-3-yl)thiazoles
View Patent ↗The invention disclosed in this document is related to the field of processes to produce certain 2-(pyridine-3-yl)thiazoles as intermediates for the synthesis of pesticidal thiazole amides.
1. A process comprising
(i) cyclizing compound (I) with compound (II) to produce compound (III);
wherein
(A) each R 1 is H, alkyl;
(B) R 2 is unsubstituted (C 1 -C 6 )alkyl; and
(C) R 3 is H
wherein step a is conducted in a polar protic solvent.
2. A process according to claim 1 wherein step a said polar protic solvent is selected from the group consisting of n-butanol, isopropanol, n-propanol, ethanol, methanol, acetic acid, water, or a mixture thereof.
3. A process according to claim 2 wherein said polar protic solvent is methanol.
4. A process according to claims 1 , 2 , or 3 , said process further comprising halogenating said R 3 to F, Cl, Br, or I
wherein said halogenating is conducted in a polar solvent and said halogenating is conducted at a temperature from 0 ° C. to ambient.
5. A process according to claim 4 wherein said halogenating is conducted in a polar solvent selected from the group consisting of dichloromethane, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, and dimethyl sulfoxide.
6. A process according to claim 5 wherein said solvent is dichloromethane.
7. A process according to claim 6 wherein R 3 is Cl.
8. A process according to claim 1 wherein R 2 is methyl.