Sodium Hydroxide → 3,4-Dihydro-2H-pyrido[3,2-b]-1,4-oxazin-2-ylmethanol

HRID 991657Notes

Reaction equation

C([O:3][C:4]([CH:6]1[O:11][C:10]2[CH:12]=[CH:13][CH:14]=[N:15][C:9]=2[NH:8][C:7]1=O)=O)C.[H-].[H-].[H-].[H-].[Li+].[Al+3].[OH-].[Na+]>C1COCC1>[O:11]1[CH:6]([CH2:4][OH:3])[CH2:7][NH:8][C:9]2[N:15]=[CH:14][CH:13]=[CH:12][C:10]1=2

Participants

Conditions

Temperature: 45 °C

Procedure

A solution of 3,4-dihydro-3-oxo-2H-pyrido[3,2-b]-1,4-oxazin-2-carboxylic acid ethyl ester (1.10 g, 5.0 mmol) in THF (50 mL) was added over 5 min to a stirred mixture of LiAlH4 (0.38 g, 10 mmol) and THF (20 mL) at 40° C. The mixture was stirred at 45° C. for 30 min and at reflux for 4 h. The mixture was allowed to attain room temperature and excess LiAlH4 decomposed with 50% aqueous NaOH. The mixture was filtered through Celite, and the filtrate was concentrated. The residue (0.42 g) was extracted with CH2Cl2 and the extract was concentrated and purified by chromatography on silica gel (gradient: PhMe to PhMe/MeOH/Et3N, 8:1:1) to give the product as a white solid: yield 0.11 g (13%); mp 123-124° C. Anal. (C8H10N2O2) C, H, N.

Workup

temperatureat reflux for 4 h
customto attain room temperature
filtrationThe mixture was filtered through Celite
concentrationthe filtrate was concentrated
extractionThe residue (0.42 g) was extracted with CH2Cl2
concentrationthe extract was concentrated
custompurified by chromatography on silica gel (gradient: PhMe to PhMe/MeOH/Et3N, 8:1:1)

Sources & evidence

ORD record: ord-82982706dfde4e76b122e5b3dbf3d564
Source dataset: uspto-grants-2002_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06465467B1

Reaction notes

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