Di-tert-butyl dicarbonate → 6-amino-5-methyl-4H-3,1-benzoxazin 2,4-dione

HRID 843706Notes

Reaction equation

HRID 843706 reaction equation
[CH3:1][C:2]1[C:7]2[C:8](=[O:13])[O:9][C:10](=[O:12])[NH:11][C:6]=2[CH:5]=[CH:4][C:3]=1[N+:14]([O-])=O.C(OC(OC(OC(C)(C)C)=O)=O)(C)(C)C.[H][H]>CN(C=O)C.[OH-].[OH-].[Pd+2]>[NH2:14][C:3]1[CH:4]=[CH:5][C:6]2[NH:11][C:10](=[O:12])[O:9][C:8](=[O:13])[C:7]=2[C:2]=1[CH3:1]

Participants

6

Reactant 3

HCID 90495Di-tert-butyl dicarbonateHCID 219011545-Methyl-6-nitro-1H-benzo[d][1,3]oxazine-2,4-dioneHCID 178418361HCID 178418361, compound

Product 1

HCID 234446576-amino-5-methyl-4H-3,1-benzoxazin 2,4-dioneYield 87.3%

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 6228DimethylformamideSolvent

Procedure

A mixture of the product of step B (13.5 g, 60.8 mmol), di-tert-butyldicarbonate (6.53 g, 30 mmol) and 20% Pd(OH)2/C (2.5 g) in 200 mL of DMF was stirred under 5 psi of hydrogen for 20 hours. The catalyst was filtered and the filtrate was evaporated under reduced pressure. The resulting yellow solid was triturated with Et2O, filtered, washed with Et2O and dried affording 10.2 g (87%) of 6-amino-5-methyl-4H-3,1-benzoxazin 2,4-dione. This material (9.0 g, 46.8 mmol) was redissolved in 100 mL of DMF and 15.35 g (70 mmol) of di-tert-butyldicarbonate was added followed by a catalytic amount of DMAP was added. The reaction mixture was stirred at room temperature under nitrogen overnight (ca. 30 hours). The reaction mixture was diluted with 200 mL of 1/2 saturated NaCl, filtered, washed with water then with hexane and dried affording 11.1 g (81%) of 1,1-dimethylethyl(1,4-dihydro-5-methyl-2,4-dioxo-2H-3,1-benzoxazin-6-yl)carbamate: Anal. Calc'd. for C14H16N2O5: C, 57.53; H. 5.52; N, 9.58. Found: C, 57.47; H, 5.80; N, 9.59.

Workup

  1. filtrationThe catalyst was filtered
  2. customthe filtrate was evaporated under reduced pressure
  3. customThe resulting yellow solid was triturated with Et2O
  4. filtrationfiltered
  5. washwashed with Et2O
  6. customdried

Sources & evidence

ORD record
ord-a16e6e034f2e4f49a4d8aca9763b45af
Source dataset
uspto-grants-2002_04
Patent number
US06380189B1

Reaction notes

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