Pyridine → HCID 19612688, compound

HRID 1600466Notes

Reaction equation

HRID 1600466 reaction equation
N1C=CC=CC=1.O[C:8]1[C:9]([CH3:24])=[C:10]([CH3:23])[C:11]2[O:16][C:15]([CH3:20])([C:17]([O-:19])=O)[CH2:14][CH2:13][C:12]=2[C:21]=1[CH3:22].C([Cl:28])(=O)C.C(=O)([O-])O.[Na+].C1C[O:37][CH2:36][CH2:35]1>O>[C:36]([C:8]1[C:9]([CH3:24])=[C:10]([CH3:23])[C:11]2[O:16][C:15]([CH3:20])([C:17]([Cl:28])=[O:19])[CH2:14][CH2:13][C:12]=2[C:21]=1[CH3:22])(=[O:37])[CH3:35]

Participants

7

Reactant 5

HCID 1049PyridineHCID 6367Acetyl chlorideHCID 8028TetrahydrofuranHCID 516892Sodium BicarbonateHCID 23503800HCID 23503800, compound

Product 1

HCID 19612688HCID 19612688, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a 1 liter round bottom flask with an atmosphere of di-nitrogen was added dry pyridine (10.00 g, excess mole) and dry THF solvent to dissolve 3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-1-benzopyran-2-carboxylate (24.9 g). The temperature was reduced to 0° C. and acetyl chloride (15 ml) slowly added with agitation. The solution was observed to be yellow. The solution was allowed to warm up to ambient temperature and then refluxed for 1 hour. The solution was cooled, reduced in volume (100 ml) and water added with a sodium hydrogen carbonate (1 g). The solution was extracted three times with DCM, the DCM dried (sodium sulphate) and evaporated to dryness. The hydroxy acetyl was redissolved in dry THF (100 ml) and oxalyl chloride (10% solution 50 ml, excess) was slowly added at 10° C. under an atmosphere of di-nitrogen. The solution was allowed to warm to ambient temperature and stirred for 12 hours. The clear solution was evaporated to dryness at 50° C. and 10 mbar to give 3,4-dihydro-6-acetyl-2,5,7,8-tetramethyl-1-benzopyran-2-carbonyl chloride. The solid was washed with saturated sodium bicarbonate and vacuum dried. A carbon 13 NMR clearly showed the aromatic ring and the acetyl functionality.

Workup

  1. customwas reduced to 0° C.
  2. temperaturerefluxed for 1 hour
  3. temperatureThe solution was cooled
  4. extractionThe solution was extracted three times with DCM
  5. dry with materialthe DCM dried (sodium sulphate)
  6. customevaporated to dryness
  7. dissolutionThe hydroxy acetyl was redissolved in dry THF (100 ml)
  8. additionoxalyl chloride (10% solution 50 ml, excess) was slowly added at 10° C. under an atmosphere of di-nitrogen
  9. temperatureto warm to ambient temperature
  10. customThe clear solution was evaporated to dryness at 50° C.

Sources & evidence

ORD record
ord-e5b3d6f7ce614a1b99c986b1b9831788
Source dataset
uspto-grants-1999_11
Patent number
US05976397

Reaction notes

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