Sodium Bicarbonate → Proxicromil

HRID 1732746Notes

Reaction equation

HRID 1732746 reaction equation
C[O:2][C:3]1[C:16]2[C:15](=[O:17])[CH:14]=[C:13]([C:18]([OH:20])=[O:19])[O:12][C:11]=2[C:10]([CH2:21][CH2:22][CH3:23])=[C:9]2[C:4]=1[CH2:5][CH2:6][CH2:7][CH2:8]2.C(=O)(O)[O-].[Na+]>Br>[OH:2][C:3]1[C:16]2[C:15](=[O:17])[CH:14]=[C:13]([C:18]([OH:20])=[O:19])[O:12][C:11]=2[C:10]([CH2:21][CH2:22][CH3:23])=[C:9]2[C:4]=1[CH2:5][CH2:6][CH2:7][CH2:8]2

Participants

4

Reactant 2

HCID 516892Sodium BicarbonateHCID 20304533HCID 20304533, compound

Product 1

HCID 65493Proxicromil

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Procedure

A suspension of 5-methoxy-4-oxo-10-propyl-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylic acid (5 g) in 48% aqueous hydrobromic acid (130 ml) was heated under reflux for 7 hours. The reaction mixture was cooled and excess saturated aqueous sodium bicarbonate added. The resulting solution was filtered, the filtrate acidified with concentrated hydrochloric acid and then extracted with chloroform (100 ml). The chloroform solution was dried (Na2SO4) and evaporated leaving a residue which, when crystallised from acetone, gave the title compound as an orange crystalline solid mp 259°-260°.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 7 hours
  3. temperatureThe reaction mixture was cooled
  4. filtrationThe resulting solution was filtered
  5. extractionextracted with chloroform (100 ml)
  6. dry with materialThe chloroform solution was dried (Na2SO4)
  7. customevaporated
  8. customleaving a residue which, when
  9. customcrystallised from acetone

Sources & evidence

ORD record
ord-c2f28c5bf7b24915ab629e175a529383
Source dataset
uspto-grants-1980_12
Patent number
US04238606

Reaction notes

Loading…