Trifluoroacetic acid → Methyl 2-oxo-2-[2-benzylperhydropyridazinyl]acetate

HRID 851943Notes

Reaction equation

[C:1]([OH:7])(C(F)(F)F)=[O:2].[CH2:8]([N:15]1[CH:20]([C:21]([O:23]C(C)(C)C)=O)[CH2:19][CH2:18][CH2:17][NH:16]1)[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.[CH2:28](N(CC)CC)C>C(Cl)Cl>[O:23]=[C:21]([CH:20]1[CH2:19][CH2:18][CH2:17][NH:16][N:15]1[CH2:8][C:9]1[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=1)[C:1]([O:7][CH3:28])=[O:2]

Participants

Conditions

Temperature: 0 °C

Procedure

20% TFA in CH2Cl2 was cooled to 0° C. and added dropwise to a solution of tert-butyl 2-benzylperhydropyridazinecarboxylate (13.34 g, 41.7 mmol) in 10 ml CH2Cl2. The mixture was stirred overnight. At this time, the mixture was cooled to 0° C. and 12.66 ml (125 mmol) triethylamine was added, followed by addition dropwise of methyl oxalyl chloride (5.62, 45.9 mmol) in 5 ml CH2Cl2. The mixture was allowed to stirred 2 hours at 0° C. and warmed up to room temperature overnight. The reaction was diluted with addition of CH2Cl2 and washed with water. The organic layer was dried over MgSO4, and filtered and concentrated. The crude product was further purified by silica chromatography to yield 9.2 g (72.4% yield) product as clear oil. 1H NMR (CDCl3, 400 MHz): δ 1.72 (m, 4H); 2.85 (m, 1H); 3.12 (m, 1H); 3.67 (s, 3H); 4.15 (m, 1H); 4.35 (m, 1H); 5.20 (m, 2H); 7.35 (m, 5H)

Workup

stirringto stirred 2 hours at 0° C.
temperaturewarmed up to room temperature overnight
washwashed with water
dry with materialThe organic layer was dried over MgSO4
filtrationfiltered
concentrationconcentrated
customThe crude product was further purified by silica chromatography

Sources & evidence

ORD record: ord-871fdc16df6543e5919d97f5200c76e3
Source dataset: uspto-grants-2007_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07253169B2

Reaction notes

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