Hydrochloric Acid → 6-(Hydroxymethyl)-2H-1,4-benzoxazin-3(4H)-one

HRID 1176206Notes

Reaction equation

[O:1]=[C:2]1[NH:7][C:6]2[CH:8]=[C:9]([C:12](OC)=[O:13])[CH:10]=[CH:11][C:5]=2[O:4][CH2:3]1.[H-].C([Al+]CC(C)C)C(C)C.Cl>O1CCCC1>[OH:13][CH2:12][C:9]1[CH:10]=[CH:11][C:5]2[O:4][CH2:3][C:2](=[O:1])[NH:7][C:6]=2[CH:8]=1

Participants

Conditions

Temperature: -40 °C

Procedure

The mixture of 6.9 g of methyl 3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylate and 230 ml of tetrahydrofuran is cooled to −40° C. Over 30 minutes, 88.9 ml of diisobutylaluminium hydride (1.5M in toluene) are added dropwise at −40° C. The reaction mixture is stirred at from −40° C. to −20° C. over 1.5 hours and subsequently poured cautiously onto 150 ml of 2N HCl (cold). The organic phase is removed and the water phase extracted with tetrahydrofuran (5×100 ml). The organic phases are washed with brine (1×100 ml), filtered through cottonwool and concentrated by evaporation. The title compound is obtained as beige crystals from the residue by crystallization (from ethanol). Rf (2:1 EtOAc-heptane)=0.16; Rt=2.23; m.p.: 186-187° C.

Workup

customThe organic phase is removed
extractionthe water phase extracted with tetrahydrofuran (5×100 ml)
washThe organic phases are washed with brine (1×100 ml)
filtrationfiltered through cottonwool
concentrationconcentrated by evaporation

Sources & evidence

ORD record: ord-7c2211534e0542bf961aed22428477ec
Source dataset: uspto-grants-2010_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07842688B2

Reaction notes

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