Hydrochloric Acid → methyl 2-[(4R)-4-allyl-3-chloro-2-oxoazetidin-1-yl]-3-methylbut-2-enoate

HRID 1719275Notes

Reaction equation

N[C@@H:2]1[C@@H:5]([CH2:6][CH:7]=[CH2:8])[N:4]([C:9](=[C:14]([CH3:16])[CH3:15])[C:10]([O:12][CH3:13])=[O:11])[C:3]1=[O:17].C(ON=O)CC(C)C.[ClH:26].C(=O)(O)[O-].[Na+]>C(Cl)Cl.C(OCC)C.C(OCC)(=O)C>[CH2:6]([C@H:5]1[N:4]([C:9](=[C:14]([CH3:16])[CH3:15])[C:10]([O:12][CH3:13])=[O:11])[C:3](=[O:17])[CH:2]1[Cl:26])[CH:7]=[CH2:8]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of methyl 2-[(3R,4R)-3-amino-4-allyl-2-oxoazetidin-1-yl]-3-methylbut-2-enoate (1.0 g) in methylene chloride (10 ml) was cooled to -65° C., and isopentylnitrite (1.01 ml) and a solution of hydrogen chloride (524 mg) in ethyl ether (8 ml) were added. The mixture was allowed to warm to 0° C. during a period of 45 minutes and stirred for one hour and half at 0° C. The reaction mixture was poured into a mixture of ethyl acetate (40 ml) and dilute aqueous sodium bicarbonate. The organic layer was separated and washed with brine, dried ove magnesium sulfate and evaporated to leave an oil, which was chromatographed on silica gel (15 g) eluting with a mixture of methylene chloride and acetone (100:2-100:5) to give methyl 2-[(4R)-4-allyl-3-chloro-2-oxoazetidin-1-yl]-3-methylbut-2-enoate (658 mg) as an oil.

Workup

customat 0° C
customThe organic layer was separated
washwashed with brine
dry with materialdried ove magnesium sulfate
customevaporated
customto leave an oil, which
customwas chromatographed on silica gel (15 g)
washeluting with a mixture of methylene chloride and acetone (100:2-100:5)

Sources & evidence

ORD record: ord-396a8ba08c334ec69e8a700ad8e7483d
Source dataset: uspto-grants-1985_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04539152

Reaction notes

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