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

Participants

Reaction Steps

To a mixture of 6.9 g of 3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-carboxylic acid methyl ester [604756-32-3] in 230 ml of tetrahydrofuran are added 88.9 ml of diisobutylaluminiumhydride (1.5M in toluene) at −40° C. The reaction mixture is stirred for 1.5 hours at −40° C. to −20° C. and poured into 150 ml of 2N hydrochloric acid. The organic phase is separated, washed with brine, dried over sodium sulfate and concentrated under reduced pressure. The residue is crystallized from ethanol to afford the title compound as a beige solid. Rf=0.16 (EtOAc-heptan 2:1); Rt=2.23, m.p.: 186-187° C.

Provenance & Evidence