p-Toluenesulfonic acid → 3,4-Methylenedioxyphenyl-4,5-dicarboethoxy-1,3-dioxolane

HRID 1491564Notes

Reaction equation

HRID 1491564 reaction equation
[CH:1]1[C:6]([CH:7]=[O:8])=[CH:5][C:4]2[O:9][CH2:10][O:11][C:3]=2[CH:2]=1.C(OCC)(OCC)OCC.C1(C)C=CC(S(O)(=O)=O)=CC=1.[C:33]([C@@H:38]([C@H:40]([C:42]([O:44][CH2:45][CH3:46])=[O:43])[OH:41])O)([O:35][CH2:36][CH3:37])=[O:34]>C1(C)C=CC=CC=1>[CH2:10]1[O:11][C:3]2[CH:2]=[CH:1][C:6]([CH:7]3[O:41][CH:40]([C:42]([O:44][CH2:45][CH3:46])=[O:43])[CH:38]([C:33]([O:35][CH2:36][CH3:37])=[O:34])[O:8]3)=[CH:5][C:4]=2[O:9]1

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 8438PiperonalHCID 31214Ethyl orthoformateHCID 6993580Diethyl tartrate

Product 1

HCID 189533313,4-Methylenedioxyphenyl-4,5-dicarboethoxy-1,3-dioxolaneYield 67%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
25 °C

Procedure

A mixture of piperonal (60 g, 0.4 mol), triethyl orthoformate (59.2 g, 0.4 mol), toluene (250 mL) and p-toluenesulfonic acid (2 g, 0.01 mol) was heated at 100°-110° C. for 0.5 h. Diethyl L-tartrate (103 g, 0.5 mol) was added to the hot solution over a 10 min. period. The mixture was then heated at reflux for 2 h. Subsequently over a 3 hour period, distillate (150 mL) was collected (pot temperature 84° C. to 110° C). The mixture was cooled (25° C.) and washed with sodium bicarbonate solution (2×50 mL) and brine (1×50 mL). Evaporation of solvents under reduced pressure provided 130.7 g of crude product. Recrystallization from methanol provided 90 g (67% yield) of (4R,5R)-2-(3,4-methylenedioxyphenyl-4,5-dicarboethoxy-1,3-dioxolane, mp 39°-40° C., [α]D25 -34.8° (c, 1.0 methanol). 1H-NMR (CDCl3)δ7.12 (1H,d,J=1.5 Hz), 7.03 (1H,dd,J= 1.5 Hz and 7.9 Hz), 6.80 (1H,d,J=7.9 Hz), 6.06 (1H,s), 5.97 (2H,s), 4.91 (1H,d,J=4.0 Hz), 4.80 (1H,d,J=4.0 Hz), 4.36-4.26 (4H, 2 q, overlapping, J=7.0 Hz), 1.38-1.30 (6H, 2 t, overlapping, J=7.0 Hz). IR (KBr) 2980, 2900, 1735, 1490, 1445, 1415 cm-1. MS m/e (% abundance) 338 (3), 265 (16), 166 (100), 149 (96), 135 (54), 121 (35), 93 (10), 65 (12), 43 (8).

Workup

  1. temperaturewas heated at 100°-110° C. for 0.5 h
  2. temperatureThe mixture was then heated
  3. temperatureat reflux for 2 h
  4. distillationSubsequently over a 3 hour period, distillate (150 mL) was collected (pot temperature 84° C. to 110° C)
  5. washwashed with sodium bicarbonate solution (2×50 mL) and brine (1×50 mL)
  6. customEvaporation of solvents under reduced pressure
  7. customprovided 130.7 g of crude product
  8. customRecrystallization from methanol

Sources & evidence

ORD record
ord-421dd91bc55142008238ef1baed5461c
Source dataset
uspto-grants-1994_12
Patent number
US05371069

Reaction notes

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