Acetic Anhydride → HCID 67887508, compound

HRID 1086639Notes

Reaction equation

HRID 1086639 reaction equation
O[CH:2]1[C:7]([CH3:9])([CH3:8])[O:6][C:5]2[CH:10]=[CH:11][S:12][C:4]=2[CH:3]1[N:13]1[CH2:17][CH2:16][CH2:15][C:14]1=[O:18].[K+].[Br-].[C:21]([O:24]C(=O)C)(=[O:23])[CH3:22]>Cl(O)(=O)(=O)=O>[C:21]([O:24][C:11]1[S:12][C:4]2[CH:3]([N:13]3[CH2:17][CH2:16][CH2:15][C:14]3=[O:18])[CH2:2][C:7]([CH3:9])([CH3:8])[O:6][C:5]=2[CH:10]=1)(=[O:23])[CH3:22]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 253877Potassium BromideHCID 99034645,6-Dihydro-6-hydroxy-5,5-dimethyl-7-(2-oxopyrrolidin-1-yl)-7H-thieno[3,2-b]pyran

Product 1

HCID 67887508HCID 67887508, compound

Reagents, catalysts & solvents 1

HCID 24247Perchloric AcidCatalyst

Procedure

A solution of 5,6-dihydro-6-hydroxy-5,5-dimethyl-7-(2-oxopyrrolidin-1-yl)-7H-thieno[3,2-b]pyran (2.0 g, 7.48 mmol) and perchloric acid (70%, 10 drops) in acetic anhydride (20 mL) were stirred for 1 h at 0°-5° C. The solution was poured into ice water (100 mL). The product was extracted into dichloromethane, washed with water (4×), and evaporated in vacuo. The resultant oil was purified by flash chromatography, using 1% methanol in dichloromethane as the eluant, then crystallized from hexanes to give the product, 2.12 g (92%), as a colorless solid: mp 92°-93° C.; IR (KBr): 1745 and 1684 cm-1 ; MS: 310 (MH+); 1H NMR (CDCl3): δ1.37(s, 3H), 1.38(s, 3H), 1.98(m, 2H), 2.10(s, 3H), 2.37(m, 2H), 3.24(m, 1 H), 3.40(m, 1H), 5.15(d, J=9.1 Hz, 1H), 5.44(d, J=9.1 Hz, 1H), 6.58(d, J=5.4 Hz, 1H) and 7.13(d, J=5.4 Hz, 1H).

Workup

  1. extractionThe product was extracted into dichloromethane
  2. washwashed with water (4×)
  3. customevaporated in vacuo
  4. customThe resultant oil was purified by flash chromatography
  5. customcrystallized from hexanes
  6. customto give the product, 2.12 g (92%)

Sources & evidence

ORD record
ord-afa3ca739d334fe5b5973616203b44e9
Source dataset
uspto-grants-1991_07
Patent number
US05030736

Reaction notes

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