2-Amino-5-bromo-1,3,4-thiadiazole → 2-Bromo-5-nitro-1,3,4-thiadiazole

HRID 1798295Notes

Reaction equation

HRID 1798295 reaction equation
[N:1]([O-:3])=[O:2].[Na+].[Br:5][C:6]1[S:10][C:9](N)=[N:8][N:7]=1>O.Cl.[Cu]>[Br:5][C:6]1[S:10][C:9]([N+:1]([O-:3])=[O:2])=[N:8][N:7]=1

Participants

6

Reactant 2

HCID 36508832-Amino-5-bromo-1,3,4-thiadiazoleHCID 23668193Sodium Nitrite

Product 1

HCID 122078702-Bromo-5-nitro-1,3,4-thiadiazoleYield 48.5%

Reagents, catalysts & solvents 3

HCID 23978CopperCatalystHCID 313Hydrochloric AcidSolvent2×HCID 962WaterSolvent

Procedure

To a stirred solution of NaNO2 (116 g, 1.68 mol) in water (1200 mL) was added copper metal powder (72 g, 1.12 mol) and 1.2 mL conc. HCl. Thereafter, 5-bromo-1,3,4-thiadiazol-2-amine (100 g, 0.56 mol) was warmed to dissolve in 4 M aq. HCl (120 mL) and added potionwise. The mixture was stirred at r.t. for 3 hrs. The precipitated yellow solid was filtered and washed with water. The solid was dissolved in ether, filtered and the filtrate concentrated in vacuo to give 2-bromo-5-nitro-[1,3,4]thiadiazole (57 g, 88% purity in HPLC, 48% yield).

Workup

  1. additionadded potionwise
  2. filtrationThe precipitated yellow solid was filtered
  3. washwashed with water
  4. dissolutionThe solid was dissolved in ether
  5. filtrationfiltered
  6. concentrationthe filtrate concentrated in vacuo

Sources & evidence

ORD record
ord-8e25cb5cae3c4ff78e4e8f491f9b1f2a
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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