Phosphoric Acid → 4,4-Dimethylthiochroman

HRID 1762725Notes

Reaction equation

HRID 1762725 reaction equation
[CH3:1][C:2](O)([CH2:4][CH2:5][S:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)[CH3:3].OP(O)(O)=O.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O>[Na]>[CH3:1][C:2]1([CH3:3])[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[S:6][CH2:5][CH2:4]1

Participants

5

Reactant 3

HCID 1004Phosphoric AcidHCID 14812Phosphorus oxide (P4O10)HCID 144422552-Methyl-4-(phenylthio)-2-butanol

Product 1

HCID 110194304,4-DimethylthiochromanYield 86.2%

Reagents, catalysts & solvents 1

HCID 5360545SodiumSolvent

Procedure

A mixture of 15.00 grams (0.076 mol) of 2-methyl-4-(phenylthio)-2-butanol, 12.75 grams of H3PO4, 27.0 grams (0.190 mol) of P2O5 [this is added in three equal portions every 8 h]and 60 mL of sodium-dried benzene was boiled under N2 for 24 hours in a 250-mL, round-bottom flask equipped with a condenser and nitrogen inlet. The resulting, cooled heterogeneous mixture was separated and the P2O5 layer was extracted with ether. The combined organic layers were washed with H2O, brine, dried with Na2SO4 (4 h). Evaporation and vacuum distillation gave 11.68 grams (86.0%) of 4,4-dimethylthiochroman as a clear colorless liquid: bp 75°-82° C./0.1 mm; 1H NMR (DCCl3) δ1.29 [s, 6 H, (CH3)2C]1.92 [m, 2 H, ArSCH2CH2 ]3.00 [m, 2 H, ArSCH2CH2 ]6.90-7.32 [m, 4 H, Ar-H]; 13C NMR (DCCl3) ppm 22.8 [ArSCH2CH2 ], 29.9 [(CH3)2C]32.6 [(CH3)C], 37.4 [ArSCH2CH2 ], 123.7, 125.7, 126.1, 126.2, 131.5, 141.5. ##STR13##

Workup

  1. customequipped with a condenser and nitrogen inlet
  2. temperatureThe resulting, cooled heterogeneous mixture
  3. customwas separated
  4. extractionthe P2O5 layer was extracted with ether
  5. washThe combined organic layers were washed with H2O, brine
  6. dry with materialdried with Na2SO4 (4 h)
  7. customEvaporation and vacuum distillation

Sources & evidence

ORD record
ord-22a3516baec940058e06548ffc95ca5f
Source dataset
uspto-grants-1989_05
Patent number
US04833254

Reaction notes

Loading…