Isobutyraldehyde → 3,4-dihydro-4-isobutyl-7-nitro-2H-1,4-benzoxazine

HRID 990929Notes

Reaction equation

[N+:1]([C:4]1[CH:13]=[CH:12][C:7]2[NH:8][CH2:9][CH2:10][O:11][C:6]=2[CH:5]=1)([O-:3])=[O:2].[CH:14](=O)[CH:15]([CH3:17])[CH3:16].[BH3-]C#N.[Na+]>>[CH2:14]([N:8]1[C:7]2[CH:12]=[CH:13][C:4]([N+:1]([O-:3])=[O:2])=[CH:5][C:6]=2[O:11][CH2:10][CH2:9]1)[CH:15]([CH3:17])[CH3:16]

Participants

Reactant 3

HCID 6561Isobutyraldehyde

HCID 5003444Sodium cyanoborohydride

HCID 184161517-Nitro-3,4-dihydro-2H-1,4-benzoxazine

Product 1

HCID 166593113,4-dihydro-4-isobutyl-7-nitro-2H-1,4-benzoxazineYield 100.6%

Procedure

This compound was prepared by General Method 3 (EXAMPLE 1) from 3,4-dihydro-7-nitro-2H-1,4-benzoxazine (EXAMPLE 1) (550 mg, 3.0 mmol), isobutyraldehyde (1.65 g, 22.8 mmol) and NaBH3CN (959 mg, 15 mmol) to afford 713 mg (99%) of 3,4-dihydro-4-isobutyl-7-nitro-2H-1,4-benzoxazine, an yellow solid. Data for 3,4-dihydro-4-isobutyl-7-nitro-2H-1,4-benzoxazine: Rf 0.75 (3:2 EtOAc:hexanes); 1H NMR (400 MHz, CDCl3) δ 7.78 (dd, 1H, J=9.0, 2.6), 7.66 (d, 1H, J=2.6), 6.55 (d, 1H, J=9.2), 4.21 (t, 2H, J=4.5), 3.52 (t, 2H, J=4.6), 3.16 (d, 2H, J=7.4), 3.12 (hept, 1H, J=6.9), 0.97 (d, 6H, J=6.7).

Sources & evidence

ORD record: ord-3fa725b4d3b84b339505baa6391ffb25
Source dataset: uspto-grants-2002_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06462038B1

Reaction notes

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