Benzene → 4,4-Dimethylthiochroman

HRID 1193613Notes

Reaction equation

HRID 1193613 reaction equation
C1([CH:7]([S:12]C(C2C=CC=CC=2)C=C(C)C)[CH:8]=[C:9]([CH3:11])[CH3:10])C=CC=CC=1.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.P(=O)(O)(O)O.[CH:43]1[CH:48]=[CH:47][CH:46]=[CH:45][CH:44]=1>>[CH3:10][C:9]1([CH3:11])[C:48]2[C:43](=[CH:44][CH:45]=[CH:46][CH:47]=2)[S:12][CH2:7][CH2:8]1

Participants

5

Reactant 4

HCID 241BenzeneHCID 1004Phosphoric AcidHCID 14812Phosphorus oxide (P4O10)HCID 54518102Phenyl-3-methylbut-2-enylsulfide

Product 1

HCID 110194304,4-Dimethylthiochroman

Procedure

To a solution of 15.48 g (86.824 mmol) of phenyl-3-methylbut-2-enylsulfide (from Example 1) in 160 ml benzene were added successively 12.6 g (88.767 mmol) of phosphorus pentoxide and 11 ml of 85% phosphoric acid. This solution was refluxed with vigorous stirring under argon for 20 hours, then cooled to room temperature. The supernatant organic layer was decanted and the syrupy residue extracted with 3×50 ml ether. Organic fractions were combined and washed with water, saturated NaHCO3 and saturated NaCl solutions and then dried (MgSO4). Solvent was removed in vacuo and the residue purified by kugelrohr distillation (80° C., 0.5 mm) to give the title compound as a pale yellow oil. PMR (CDCl3) :δ 1.30 (6H, s), 1.90-1.95 (2H, m), 2.95-3.00 (2H, m), 6.96-7.00 (2H, m), 7.04-7.07 (1H, m), 7.30-7.33 (1H, m).

Workup

  1. temperatureThis solution was refluxed
  2. customThe supernatant organic layer was decanted
  3. extractionthe syrupy residue extracted with 3×50 ml ether
  4. washwashed with water, saturated NaHCO3 and saturated NaCl solutions
  5. dry with materialdried (MgSO4)
  6. customSolvent was removed in vacuo
  7. distillationthe residue purified by kugelrohr distillation (80° C., 0.5 mm)

Sources & evidence

ORD record
ord-72ebdfee4bfd4bd4be6e2652b8a8d169
Source dataset
uspto-grants-1989_03
Patent number
US04810804

Reaction notes

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