Hydrazine hydrate (1:1) → Methyl 7-amino-2,3-dihydro-1,4-benzodioxin-6-carboxylate

HRID 1908958Notes

Reaction equation

HRID 1908958 reaction equation
O.NN.[N+:4]([C:7]1[C:8]([C:17]([O:19][CH3:20])=[O:18])=[CH:9][C:10]2[O:15][CH2:14][CH2:13][O:12][C:11]=2[CH:16]=1)([O-])=O>CO.[Pd]>[NH2:4][C:7]1[C:8]([C:17]([O:19][CH3:20])=[O:18])=[CH:9][C:10]2[O:15][CH2:14][CH2:13][O:12][C:11]=2[CH:16]=1

Participants

5

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 10537941Methyl 7-Nitro-1,4-benzodioxane-6-carboxylate

Product 1

HCID 3146109Methyl 7-amino-2,3-dihydro-1,4-benzodioxin-6-carboxylateYield 50.4%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent2×

Procedure

A solution of hydrazine monohydrate (1.0 mL, 21 mmol) in MeOH (3 mL) was added dropwise to a refluxing suspension of methyl 7-nitro-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylate (889 mg, 3.7 mmol) and palladium on carbon (10%, 220 mg) in MeOH (25 mL) under N2. After refluxing overnight, the resulting mixture was cooled to room temperature, filtered through celite and the filter cake was washed with MeOH. The combined filtrates were concentrated under reduced pressure and the residue was purified by column chromatography on silica gel eluting with 30% ethyl acetate in hexane to yield methyl 7-amino-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylate (390 mg, 50%). 1H NMR (CDCl3, 600 MHz) δ 7.19 (s, 1H), 6.17 (s, 1H), 4.24-4.22 (m, 2H), 4.17-4.15 (m, 2H), 3.82 (s, 3H); MS (ES+) m/z 210.1 (M+H)+

Workup

  1. temperatureAfter refluxing overnight
  2. filtrationfiltered through celite
  3. washthe filter cake was washed with MeOH
  4. concentrationThe combined filtrates were concentrated under reduced pressure
  5. customthe residue was purified by column chromatography on silica gel eluting with 30% ethyl acetate in hexane

Sources & evidence

ORD record
ord-ff39310cbf9b4ffeae75d7f1c5107b64
Source dataset
uspto-grants-2013_12
Patent number
US08598342B2

Reaction notes

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