Granted Patent
B2
US 9,718,783 · App. 15/339,190 · Granted Aug 1, 2017
Process for the preparation of 4-alkoxy-3-hydroxypicolinic acids
Inventors:
James M. Renga (Spokane, WA); Yuanming Zhu (Carmel, IN); Gregory T. Whiteker (Carmel, IN); Nakyen Choy (Carmel, IN); Kenneth E. Stockman (Midland, MI)
Assignee:
Dow AgroSciences LLC
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Abstract
4,6-Dibromo-3-hydroxypicolinonitrile may be prepared from furfural in a series of chemical steps selected from cyano-amination, amine salt formation and bromination-rearrangement. 4-Alkoxy-3-hydroxypicolinic acids may be conveniently prepared from 4,6-dibromo-3-hydroxypicolinonitrile in a series of chemical steps selected from bromo substitution, nitrile hydrolysis and halogen reduction.
Claims (7)
1. A process for preparing the compound of Formula H
comprises the steps of:
a) creating a mixture which includes the compound of Formula F,
wherein R 1 is a C 1 -C 3 alkyl;
a strong base, zinc metal, and water;
b) heating the mixture; and
c) isolating the compound of Formula H from the mixture.
Assignments (2)
CHANGE OF NAME
Recorded Nov 8, 2021
From: DOW AGROSCIENCES LLC
To: CORTEVA AGRISCIENCE LLC
Reel/Frame 058044/0184 →
ASSIGNMENT OF ASSIGNOR'S INTEREST
Recorded Feb 1, 2017
From: RENGA, JAMES M; ZHU, YUANMING; WHITEKER, GREGORY T; CHOY, NAKYEN; STOCKMAN, KENNETH E
To: DOW AGROSCIENCES LLC
Reel/Frame 041588/0061 →
Continuity (3)
Provisional Application
62021876
· Jul 8, 2014