Potassium Nitrate → ethyl 9',10'-difluoro-8'-nitro-7'-oxospiro[cyclobutane-1,3'(2'H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6'-carboxylate

HRID 444763Notes

Reaction equation

HRID 444763 reaction equation
[F:1][C:2]1[C:3]([F:24])=[C:4]2[O:9][CH2:8][C:7]3([CH2:12][CH2:11][CH2:10]3)[N:6]3[CH:13]=[C:14]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:15](=[O:18])[C:16]([CH:17]=1)=[C:5]23.[N+:25]([O-])([O-:27])=[O:26].[K+]>OS(O)(=O)=O>[F:1][C:2]1[C:3]([F:24])=[C:4]2[O:9][CH2:8][C:7]3([CH2:10][CH2:11][CH2:12]3)[N:6]3[CH:13]=[C:14]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:15](=[O:18])[C:16]([C:17]=1[N+:25]([O-:27])=[O:26])=[C:5]23

Participants

4

Reactant 2

HCID 24434Potassium NitrateHCID 58134828Ethyl 9',10'-difluoro-7'-oxospiro[cyclobutane-1,3'(2'H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6'-carboxylate

Product 1

HCID 58134645ethyl 9',10'-difluoro-8'-nitro-7'-oxospiro[cyclobutane-1,3'(2'H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6'-carboxylateYield 91.2%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

A solution of ethyl 9′,10′-difluoro-7′-oxospiro[cyclobutane-1,3′(2′H)-[7H]pyrido[1,2,3-de][1,4]benzoxazine]-6′-carboxylate (580 mg, 1.73 mmol) in concentrated H2SO4 (7 mL) was treated portion wise at 0° C. with solid KNO3 (245 mg, 2.42 mmol). The reaction mixture was stirred for 1 hour at 0° C. and poured into ice-water. The resulting precipitate was collected by filtration, washed with water and dried to yield the title compound (600 mg, 91%) as a pale yellow solid. 1H-NMR (400 MHz, DMSO-d6) δ 1.30 (3H, t, J=7.3 Hz), 1.93-2.09 (2H, m), 2.16-2.25 (2H, m), 2.73-2.80 (2H, m), 4.26 (2H, q, J=7.3 Hz), 4.69 (2H, s), 8.87 (1H, s). ESIMS (+): 381 [M+H]+.

Workup

  1. filtrationThe resulting precipitate was collected by filtration
  2. washwashed with water
  3. customdried

Sources & evidence

ORD record
ord-243913efc5164a98b210a72d047919f3
Source dataset
uspto-grants-2013_07
Patent number
US08476261B2

Reaction notes

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