tert-butyl N-hydroxycarbamate → 2-t-butoxycarbonyl-3,6-dihydro-3,5-dimethyl-6-(4-ethoxyphenyl)-2H-1,2-oxazine

HRID 1018474Notes

Reaction equation

[OH:1][NH:2][C:3](=[O:9])[O:4][C:5]([CH3:8])([CH3:7])[CH3:6].[CH2:10]([O:12][C:13]1[CH:18]=[CH:17][C:16](/[CH:19]=[C:20](\[CH3:24])/[CH:21]=[CH:22]/[CH3:23])=[CH:15][CH:14]=1)[CH3:11].I([O-])(=O)(=O)=O.C([N+](CCCC)(CCCC)CCCC)CCC>ClCCl>[C:5]([O:4][C:3]([N:2]1[CH:22]([CH3:23])[CH:21]=[C:20]([CH3:24])[CH:19]([C:16]2[CH:15]=[CH:14][C:13]([O:12][CH2:10][CH3:11])=[CH:18][CH:17]=2)[O:1]1)=[O:9])([CH3:8])([CH3:7])[CH3:6]

Participants

Conditions

Temperature: 4 °C

Procedure

A solution of t-butyl N-hydroxycarbamate (11.14 g, 84 mmol) in dichloromethane (300 ml) was added dropwise over 25 mins to a stirred mixture of 1-(4-ethoxyphenyl)-2-methyl-pent-1E,3E-diene (8.46 g, 42 mmol) and tetrabutylammonium periodate (32.6 g, 75 mmol) in dichloromethane (300 ml) cooled to 4° C. under nitrogen atmosphere. After stirring for 4 h at 3-4° C. the reaction mixture was washed with 2M aqueous sodium carbonate containing sodium metabisulphite and then twice with water. The dichloromethane solution was dried over magnesium sulphate, filtered and evaporated to an oil (33.1 g). This was purified by chromatography twice on silica eluting with n-hexane: diethyl ether 4:1 to give 2-t-butoxycarbonyl-3,6-dihydro-3,5-dimethyl-6-(4-ethoxyphenyl)-2H-1,2-oxazine as a yellow oil.

Workup

washwas washed with 2M aqueous sodium carbonate
additioncontaining sodium metabisulphite
dry with materialThe dichloromethane solution was dried over magnesium sulphate
filtrationfiltered
customevaporated to an oil (33.1 g)
customThis was purified by chromatography twice on silica eluting with n-hexane: diethyl ether 4:1

Sources & evidence

ORD record: ord-6c5fad7f5fbe475c8a4f306fa135e6b7
Source dataset: uspto-grants-2002_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06482824B1

Reaction notes

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