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US 6,998,502 B1Granted
Convenient process of manufacture for difluoromethylornithine and related compounds
AssigneeSabinsa Corporation
InventorsMuhammed Majeed, Kalyanam Nagabhushanam, Keshava Rao Rapole, Ravikrishna Chebolu
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Abstract
A process for the manufacture of α-Difluoromethylornithine, analogs and derivatives is described from ornithine hydrochloride or from Nδ-phthaloyl ornithine hydrochloride, conversion to an alkyl ester, conversion to solid derivatives through the formation of Schiff bases, subsequent halomethylation using suitable bases and hydrolysis.
Claims1
A process to manufacture-Difluoromethylornithine, its analogs and derivatives represented by formula I
- wherein
- R1 is hydrogen;
- R2 is hydroxy, C1–C8 alkoxy, —NR′R″, wherein R′ and R″ are independently hydrogen, C1–C8 alkyl groups;
- R3 is hydrogen;
- R4 is —CH2F, —CHF2, —CF3
- and the salts thereof, and the process comprising the step of hydrolyzing the halomethylated compounds of formula IIA, under acid conditions;
- wherein:
- R4 is —CH2F, —CHF2, —CF3,
- R5 is hydrogen, C1–C8 alkyl groups;
- R6 is monohalogen substituents such as o,m,p-chloro or o,m,p-bromo;
- or dihalogen substituents such as 3,4-dichloro;
- 2,6-dichloro;
- 3,4-dibromo and other positional isomers thereof;
- or polyalkoxy substituents;
- and
- R7 is C1–C4alkyl, halogens such as chlorine or bromine.
13 more elements
Dependencies are inferred from the claim text.