Sodium borohydride → HCID 19387095, compound

HRID 2399304Notes

Reaction equation

HRID 2399304 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[CH:10]([CH3:15])[C:9](=[O:16])[C:8]=2[CH:17]=1)([O-:3])=[O:2].[BH4-].[Na+]>CO>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[CH:10]([CH3:15])[CH:9]([OH:16])[C:8]=2[CH:17]=1)([O-:3])=[O:2]

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 193871946-nitro-2,2,3-trimethyl-3,4-dihydro-2H-1-benzopyran-4-one

Product 1

HCID 19387095HCID 19387095, compoundYield 104.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A suspension of 6-nitro-2,2,3-trimethyl-3,4-dihydro-2H-1-benzopyran-4-one (40 g, 0.170 mol) in methanol (400 ml) was treated with sodium borohydride (6.4 g, 0.170 mol) at room temperature. After stirring for two hours the solvent was evaporated under reduced pressure, and the residue treated with a mixture of water and dichloromethane. After stirring the organic phase was separated and evaporated under reduced pressure to give 42.2 g of 6-nitro-2,2,3-trimethyl-4-hydroxy-3,4-dihydro-2H-1-benzopyran, as an oil, 1H NMR (CDCl3): δ1.05 (d, 3H), 1.4 (s, 3H), 1.45 (s, 3H), 2.0-2.2 (m, 2H), 4.4 and 4.9 (multiplets cis and trans, 1H), 6.85 (m, 1H), 8.05 (m, 1H), 8.4 (m, 1H).

Workup

  1. customwas evaporated under reduced pressure
  2. additionthe residue treated with a mixture of water and dichloromethane
  3. stirringAfter stirring the organic phase
  4. customwas separated
  5. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-27ad90f0f4aa4aa98d88d193cca01bd2
Source dataset
uspto-grants-1995_09
Patent number
US05447943

Reaction notes

Loading…