Trimethyl orthoformate → Methyl (E)-4-Chloro-3-methoxy-2-butenoate
Reaction equation
[Cl:1][CH2:2][C:3](=[O:9])[CH2:4][C:5]([O:7][CH3:8])=[O:6].[CH:10](OC)(OC)OC>>[Cl:1][CH2:2]/[C:3](/[O:9][CH3:10])=[CH:4]\[C:5]([O:7][CH3:8])=[O:6]Participants
3
Conditions
- Temperature
- 40 °C
Procedure
A mixture of methyl 4-chloroacetoacetate (96.5 g) and trimethyl orthoformate (340.2 g) was stirred under argon with 96.5 g of Amberlyst-15 ion exchange resin. The temperature was raised to 40° C. and stirring continued for 5 hours. The resin was filtered off and the filtrate distilled under vacuum (15 mm). The distillate was mixed with 3.2 g of p-toluenesulfonic acid and heated at 150° C. until no more methanol distilled off. Distillation of the residue under vacuum gave 4-chloro-3-methoxy-2-E-butenoic acid, methyl ester, b.p. 75° C. (3 mm Hg).
Workup
- stirringstirring
- filtrationThe resin was filtered off
- distillationthe filtrate distilled under vacuum (15 mm)
- additionThe distillate was mixed with 3.2 g of p-toluenesulfonic acid
- temperatureheated at 150° C. until no more methanol
- distillationdistilled off
- distillationDistillation of the residue under vacuum
Sources & evidence
- ORD record
- ord-5b87232086344cc3989b1e8cdc699848
- Source dataset
- uspto-grants-1991_12
- Patent number
- US05072006
Reaction notes
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