Nitrogen → 2-[4-(2-Methyl-[1,3]dioxolan-2-yl)-butyl]-oxazole-4-carboxylic acid methyl ester

HRID 1189360Notes

Reaction equation

N#N.[CH3:3][O:4][C:5]([CH:7]1[CH2:11][O:10][C:9]([CH2:12][CH2:13][CH2:14][CH2:15][C:16]2([CH3:21])[O:20][CH2:19][CH2:18][O:17]2)=[N:8]1)=[O:6].C1CCN2C(=NCCC2)CC1.BrC(Cl)(Cl)Cl.C([O-])(O)=O.[Na+]>C(Cl)Cl>[CH3:3][O:4][C:5]([C:7]1[N:8]=[C:9]([CH2:12][CH2:13][CH2:14][CH2:15][C:16]2([CH3:21])[O:20][CH2:19][CH2:18][O:17]2)[O:10][CH:11]=1)=[O:6]

Participants

Conditions

Temperature: 0 °C

Procedure

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 2-[4-(2-methyl-[1,3]dioxolan-2-yl)-butyl]-4,5-dihydro-oxazole-4-carboxylic acid methyl ester (1.04 g, 3.83 mmol) in CH2Cl2 (30 mL) at 0° C. was treated with DBU (0.72 mL, 4.79 mmol). Then, bromotrichloromethane (0.95 mL, 9.58 mmol) was added dropwise over 20 min and the reaction mixture was stirred at 0° C. for 4 h then at rt overnight. Additional DBU (0.72 mL, 4.79 mmol) and bromotrichloromethane (0.95 mL, 9.58 mmol) were added at 0° C. and the reaction mixture stirred at rt for 24 h. Sat. aq. NaHCO3 was then added and the aq. phase was extracted with CH2Cl2 (3×). The combined org. extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (20:1→1:1 hept-EA) gave the title compound as a white solid. TLC: rf (1000:50:4 CH2Cl2-MeOH—NH3)=0.25. LC-MS-conditions 02: tR=0.84 min [M+H]+=270.35.

Workup

customat rt
customovernight
stirringthe reaction mixture stirred at rt for 24 h
extractionthe aq. phase was extracted with CH2Cl2 (3×)
dry with materialextracts were dried over Na2SO4
filtrationfiltered
customthe solvent was removed under reduced pressure
customPurification of the residue by FC (20:1→1:1 hept-EA)

Sources & evidence

ORD record: ord-42ced624539341ad929b671603d50ceb
Source dataset: uspto-grants-2014_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08674111B2

Reaction notes

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