2-Fluorohydrazine → Chloro Fluoro Triazolin-3-one
반응식
[F:1]NN.[F:4][C:5]1C=CC=CC=1N1C(=O)NC(C)=N1.[Cl:18][C:19]1[CH:24]=[CH:23][C:22]([N:25]2[C:29](=[O:30])[NH:28][C:27]([CH3:31])=[N:26]2)=[C:21]([F:32])[CH:20]=1>>[Cl:18][C:19]1[CH:24]=[CH:23][C:22]([N:25]2[C:29](=[O:30])[N:28]([CH:5]([F:4])[F:1])[C:27]([CH3:31])=[N:26]2)=[C:21]([F:32])[CH:20]=1참가 물질
실험 절차
While the efficiency of a multistep process to prepare a complex molecule can be improved by optimizing the yield of each step, even greater efficiency may be achieved by finding a route with fewer steps. It has now been found that the Target Herbicide may be prepared more efficiently by a new route in which there are only six steps. In the first step 2-fluorohydrazine is cyclized to 4,5-dihydro-1-(2-fluorophenyl)-3-methyl-5-oxo-1H-1,2,4-triazole, which is then chlorinated to 1-(4-chloro-2-fluorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazole. In the third step the chlorinated product is difluoromethylated, affording 1-(4-chloro-2-fluorophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazole. In an alternative, less preferred method, 4,5-dihydro-1-(2-fluorophenyl)-3-methyl-5-oxo-1H-1,2,4-triazole may first be difluoromethylated and then chlorinated. The third step intermediate is nitrated, yielding 1-(4-chloro-2-fluoro-5-nitrophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazole, which is reduced to the corresponding 1-(5-amino-4-chloro-2-fluorophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4triazole. In the final step the 5-amino derivative is subjected to diazotization/arylation, yielding the Target Herbicide.
후처리
- customWhile the efficiency of a multistep process to prepare a complex molecule
- custommay be prepared more efficiently by a new route in which there
출처 및 근거
- ORD 기록
- ord-619c0c8046884fa5931e360e0cdcf4cf
- 출처 데이터셋
- uspto-grants-1999_10
- 특허 번호
- US05965742
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