2H-Pyran-2-one, 4-methoxy-6-methyl- → Dimethyl 5-methoxy-3-methylphthalate

HRID 1360327Notes

Reaction equation

HRID 1360327 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[C:7]([CH3:9])OC(=O)[CH:4]=1.[C:11]([O:19][CH3:20])(=[O:18])[C:12]#[C:13][C:14]([O:16][CH3:17])=[O:15]>>[CH3:1][O:2][C:3]1[CH:4]=[C:13]([C:14]([O:16][CH3:17])=[O:15])[C:12]([C:11]([O:19][CH3:20])=[O:18])=[C:7]([CH3:9])[CH:8]=1

Participants

3

Reactant 2

HCID 126512H-Pyran-2-one, 4-methoxy-6-methyl-HCID 12980Dimethyl acetylenedicarboxylate

Product 1

HCID 10879167Dimethyl 5-methoxy-3-methylphthalateYield 76%

Conditions

Temperature
180 °C

Procedure

A mixture of compound K (41.4 g, 295 mmol) and dimethyl but-2-ynedioate (47.2 mL, 384 mmol) was stirred at 180° C. for 1 hour, then at 210° C. for 30 minutes. The mixture was cooled to room temperature and purified by silica gel chromatography (ethyl acetate:hexane=20:1-4:1) to give compound L (53.4 g, 76%) as a pale-yellow oil. 1H NMR (CDCl3, 400 MHz): δ 2.34 (3H, s), 3.84 (3H, s), 3.88 (3H, s), 3.90 (3H, s), 6.91 (1H, d, J=2.4 Hz), 7.29 (1H, d, J=2.4 Hz). EIMS (+): 238 [M]+

Workup

  1. waitat 210° C. for 30 minutes
  2. temperatureThe mixture was cooled to room temperature
  3. custompurified by silica gel chromatography (ethyl acetate:hexane=20:1-4:1)

Sources & evidence

ORD record
ord-4d3ee3047cad40e687d205a4ea6b1354
Source dataset
uspto-grants-2011_02
Patent number
US07879846B2

Reaction notes

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