Acetic Anhydride → HCID 67887508, compound

HRID 981495Notes

Reaction equation

HRID 981495 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].[C:19]([O:22]C(=O)C)(=[O:21])[CH3:20]>Cl(O)(=O)(=O)=O>[C:19]([O:22][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:21])[CH3:20]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 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 (4x), 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): δ 1.37 (s, 3H), 1.38 (s, 3H), 1.98 (m, 2H), 2.10 (s, 3H), 2.37 (m, 2H), 3.24 (m, 1H), 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 (4x)
  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-59fdeee4d0594468b9fa373d3846d6e2
Source dataset
uspto-grants-1991_02
Patent number
US04992435

Reaction notes

Loading…