Hydrochloric Acid → HCID 19710536, compound

HRID 726217Notes

Reaction equation

HRID 726217 reaction equation
[Cl:1]Cl.Cl.[CH3:4][O:5][C:6]1[C:7](=[O:18])[C:8]2[CH2:9]C=[CH:11][CH:12]([CH3:17])[C:13]=2[C:14](=[O:16])[CH:15]=1.[K+].[Br-].[CH:21]([Cl:24])(Cl)Cl>O=[Mn]=O>[Cl:1][CH:11]1[CH:21]([Cl:24])[CH2:9][C:8]2[C:7](=[O:18])[C:6]([O:5][CH3:4])=[CH:15][C:14](=[O:16])[C:13]=2[CH:12]1[CH3:17]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 6212Chloroform3×HCID 24526Chlorine2×HCID 253877Potassium BromideHCID 12692025HCID 12692025, compound

Product 1

HCID 19710536HCID 19710536, compound

Reagents, catalysts & solvents 1

HCID 14801Manganese dioxideCatalyst

Procedure

A solution of Cl2 in CHCl3 (freed of inhibitor by passing through a silica gel column) was prepared by adding concd HCl to stirred MnO2 and bubbling the resulting effluent through inhibitor free CHCl3. The resulting green solution was passed through a small silica gel column prior to use to remove H2O. The Cl2 concentration was not determined. To a stirred solution of 5,8-dihydro-2-methoxy-5-methylnaphthalene-1,4-dione (950 mg, 4.65 mmol) in inhibitor free CHCl3 (20 mL) the above described Cl2 solution was added in portions with stirring. The reaction was monitored by TLC (CHCl3). When the analysis indicated the total consumption of the starting material, the solvent was removed from the reaction mixture in vacuo to give a yellow oil. This was subject to column chromatography (silica gel, 2.5×25 cm column, 50% hexanes/50% CHCl3 elution). Some impurities eluted initially. The desired product eluted next as a yellow band followed closely by impurities. Solvent removal from the purest fractions yielded a yellow oil (293 mg, 80-90% pure by TLC and 1H NMR). The mixed product fraction was stripped of solvent in vacuo and the resulting yellow oil re-chromatographed in a manner similar to that described above (employed 2.5×50 cm column). Solvent removal from the purest fractions yielded an additional portion of a yellow oil (132 mg, 80-90% pure by TLC and 1H NMR; total yield 425 mg, 33%); 1H NMR (CDCl3) δ1.53 (d, J=7.5 Hz, 3H), 2.98 (m, 1H), 3.28 (m, 2H), 3.82 (s, 3H), 4.22 (m, 1H), 4.39 (dd, J1 =5.1 Hz, J2 =9.9 Hz, 1H), 6.92 (s, 1H); IR (KBr) 3325 (w), 3255 (w), 3077 (w), 2981 (m), 2940 (m), 2879 (w), 2848 (m), 1677 (s), 1674 (s), 1651 (s), 1637 (s), 1634 (s), 1609 (s), 1455 (m), 1412 (w), 1387 (w), 1372 (w), 1347 (m), 1304 (m), 1289 (m), 1226 (s), 1185 (w), 1147 (m), 1118 (m), 1089 (w), 1056 (w), 1044 (m), 1017 (m), 978 (m), 954 (m), 941 (w), 918 (m), 896 (w), 850 (m), 805 (m), 793 (m), 786 (m), 763 (m), 712 (m), 687 (m), 654 (m) cm-1.

Workup

  1. customwas prepared
  2. custombubbling the resulting effluent through inhibitor free CHCl3
  3. customto remove H2O
  4. concentrationThe Cl2 concentration
  5. additionwas added in portions
  6. customthe total consumption of the starting material
  7. customthe solvent was removed from the reaction mixture in vacuo
  8. customto give a yellow oil
  9. washThis was subject to column chromatography (silica gel, 2.5×25 cm column, 50% hexanes/50% CHCl3 elution)
  10. washSome impurities eluted initially
  11. washThe desired product eluted next as a yellow band
  12. customSolvent removal from the purest fractions
  13. customyielded a yellow oil (293 mg, 80-90% pure by TLC and 1H NMR)
  14. customthe resulting yellow oil re-chromatographed in a manner similar to
  15. customSolvent removal from the purest fractions
  16. customyielded an additional portion of a yellow oil (132 mg, 80-90% pure by TLC and 1H NMR; total yield 425 mg, 33%)

Sources & evidence

ORD record
ord-c786706d07b045e3a5425c4f073d3374
Source dataset
uspto-grants-1998_01
Patent number
US05708168

Reaction notes

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