Water → 3-cyclopentyl-2-(6-oxo-6H-pyridazin-1-yl)-propionic acid methyl ester

HRID 2381491Notes

Reaction equation

[N:1]1[NH:2][C:3](=[O:7])[CH:4]=[CH:5][CH:6]=1.[H-].[Na+].[CH3:10][O:11][C:12](=[O:21])[CH:13](Br)[CH2:14][CH:15]1[CH2:19][CH2:18][CH2:17][CH2:16]1.O>O1CCCC1>[CH3:10][O:11][C:12](=[O:21])[CH:13]([N:2]1[C:3](=[O:7])[CH:4]=[CH:5][CH:6]=[N:1]1)[CH2:14][CH:15]1[CH2:16][CH2:17][CH2:18][CH2:19]1

Participants

Conditions

Temperature: 25 °C

Procedure

A solution of 2H-pyridazin-3-one (2.0 g, 20.81 mmol) in tetrahydrofuran (104 mL, 0.2M) cooled to 0° C. was treated with a 60% dispersion of sodium hydride in mineral oil (839 mg, 24.97 mmol). The reaction was stirred at 25° C. for 30 min. After this time, the reaction was treated with 2-bromo-3-cyclopentyl-propionic acid methyl ester (Intermediate 10, 5.38 g, 22.89 mmol). The reaction was then warmed to 50° C. where it stirred overnight. After this time, the reaction was cooled to 25° C., was poured into water (150 mL) and was extracted into ethyl acetate (3×100 mL). The organics were dried over sodium sulfate, filtered and concentrated in vacuo. Silica gel column chromatography (ISCO 80 g, 30% ethyl acetate/hexanes) afforded 3-cyclopentyl-2-(6-oxo-6H-pyridazin-1-yl)-propionic acid methyl ester (3.0 g, 57%) as a tan oil; ES+-HRMS m/e calcd for C13H18N2O3 [M+H+] 251.1390 found 251.1389.

Workup

temperatureThe reaction was then warmed to 50° C. where it
stirringstirred overnight
temperatureAfter this time, the reaction was cooled to 25° C.
extractionwas extracted into ethyl acetate (3×100 mL)
dry with materialThe organics were dried over sodium sulfate
filtrationfiltered
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-4ff842d70e41456f9e2e27154fc93b4e
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08258134B2

Reaction notes

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