(4H,6H,7H-pyrazolo(3,2-c)(1,4)oxazin-2-yl)methanol → 6,7-dihydro-4H-pyrazolo(5,1-c)(1,4)oxazine-2-carbaldehyde

HRID 1158921Notes

Reaction equation

[N:1]1[N:9]2[C:4]([CH2:5][O:6][CH2:7][CH2:8]2)=[CH:3][C:2]=1[CH2:10][OH:11]>ClCCCl.[O-2].[O-2].[Mn+4]>[N:1]1[N:9]2[C:4]([CH2:5][O:6][CH2:7][CH2:8]2)=[CH:3][C:2]=1[CH:10]=[O:11]

Participants

Conditions

Temperature: 60 °C

Procedure

To a solution of 6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazin-2-ylmethanol (1.08 g, 7.0 mmol) in 1,2-dichloroethane (30 ml) was added 5.4 g of activated manganese dioxide at room temperature with stirring. The mixture was heated to 60° C. for 1 hr and then stirred at room temperature for 16 hr. The final mixture was filtered through a column of silica gel topped with celite. The filter pad was eluted with methylene chloride, followed by ethyl acetate. The ethyl acetate eluent was evaporated and the residue triturated with to give 0.81 g of a white solid; mp 91° C.; MS (ESI) m/z 153.2 (M+H).

Workup

stirringstirred at room temperature for 16 hr
filtrationThe final mixture was filtered through a column of silica gel
washThe filter pad was eluted with methylene chloride
customThe ethyl acetate eluent was evaporated
customthe residue triturated with

Sources & evidence

ORD record: ord-1c7c7d3b6dcf4194abfcefb8bc9bb978
Source dataset: uspto-grants-2010_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07812014B2

Reaction notes

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