Sulfuric Acid → HCID 59000186, compound

HRID 2241124Notes

Reaction equation

HRID 2241124 reaction equation
S(=O)(=O)(O)O.[OH:6][C:7]1[CH:16]=[C:15]2[C:10]([CH:11]([CH3:18])[CH2:12][C:13](=[O:17])[O:14]2)=[CH:9][CH:8]=1.C(Cl)(Cl)Cl.[C:23]([O-])(O)=[O:24].[Na+]>CO>[OH:14][C:15]1[CH:16]=[C:7]([OH:6])[CH:8]=[CH:9][C:10]=1[CH:11]([CH3:18])[CH2:12][C:13]([O:24][CH3:23])=[O:17]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 6212ChloroformHCID 516892Sodium BicarbonateHCID 251119877-Hydroxy-4-methyl-3,4-dihydro-2H-1-benzopyran-2-one

Product 1

HCID 59000186HCID 59000186, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

Concentrated sulfuric acid (1.2 mL, 43 mmol) was added to a solution of 7-hydroxy-3,4-dihydro-4-methylcoumarin (B1) (75.8 g, 430 mmol) in methanol (1 L) at room temperature and the solution stirred for about 16 hours. At this time, TLC (8% methanol:chloroform) showed the clean formation of product at the expense of starting material. The solution was neutralized with 7% NaHCO3 solution (50 ml) and the majority of the solvent (750 ml) removed under reduced pressure. The solution was diluted with ethyl acetate (1 L), washed successively with saturated NaHCO3: saturated NaCl (1:1, 200 ml), saturated NaCl (2×200 ml), dried (Na2SO4), filtered and the solvent removed to give an orange oil. Further purification by filtering through a short pad of silica gel and eluting with 5% methanol in chloroform afforded pure product as a pale orange gel (87 g, 98%): 1H NMR (DMSO-d6) d 1.13 (d, JJ=7.0, 3H), 2.42 (dd, JJ=15.0, 8.9, 1H), 2.58 (dd, JJ=15.0, 5.8, 1H), 3.37 (m, 1H), 3.55 (s, 3H), 6.15 (dd, JJ=8.6, 2.4, 1H), 6.28 (d, JJ=2.4, 1H), 6.84 (d, JJ=8.2, 1H), 8.93 (s, 1H), 9.11 (s, 1H); 13C NMR (DMSO-d6) d 20.16, 29.09, 40.77, 51.00, 102.55, 106.02, 122.09, 127.04, 155.18, 156.27, 172.55; m/z (EI; TMS derivatized; M+) 354; IR (neat; cm−1) 3384.5, 2969.3, 1708.9, 1621.0, 1606.3, 1518.4, 1454.9, 1367.0, 1303.5, 1220.4, 1166.7, 1108.1, 976.2, 839.4, 810.1.

Workup

  1. customthe majority of the solvent (750 ml) removed under reduced pressure
  2. additionThe solution was diluted with ethyl acetate (1 L)
  3. washwashed successively with saturated NaHCO3
  4. dry with materialsaturated NaCl (1:1, 200 ml), saturated NaCl (2×200 ml), dried (Na2SO4)
  5. filtrationfiltered
  6. customthe solvent removed
  7. customto give an orange oil
  8. customFurther purification
  9. filtrationby filtering through a short pad of silica gel
  10. washeluting with 5% methanol in chloroform afforded pure product as a pale orange gel (87 g, 98%)

Sources & evidence

ORD record
ord-357963b07aa441c99e4082efedfc6491
Source dataset
uspto-grants-2010_05
Patent number
US07723537B2

Reaction notes

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