Methanol → HCID 12719792, compound
Reaction equation
C[O:2][C:3]([C:5]1([C:12]2[CH:17]=[CH:16][C:15]([Cl:18])=[C:14]([Cl:19])[CH:13]=2)[CH2:7][CH:6]1[C:8]([O:10]C)=[O:9])=[O:4].CO.[OH-].[Na+]>O>[Cl:19][C:14]1[CH:13]=[C:12]([C:5]2([C:3]([OH:4])=[O:2])[CH2:7][CH:6]2[C:8]([OH:10])=[O:9])[CH:17]=[CH:16][C:15]=1[Cl:18]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 72.5 °C
Procedure
A mixture of 31.0 kg 1-(3,4-dichlorophenyl)-1,2-cyclopropane-dicarboxylic acid dimethyl ester (from Step 2), 40 L water, 35 kg methanol and 18.0 kg 50% caustic soda was warmed to 70-75° C. (under reflux) and maintained at 70-75° C. for 1.5 hours. 10 L water was then added, and the mixture was kept at 75-77° C. for an additional 2 hours. Methanol was slowly distilled off in vacuo to 70° C. to give a heavy suspension, which was then mixed with 80 L water to effect solution. The free dicarboxylic acid was precipitated with 31 kg of 32% hydrochloric acid and extracted with 100 kg ethyl acetate. The lower aqueous phase was separated and washed with 20 kg ethyl acetate. The combined organic phases were washed with 50 L water, and then saturated aqueous sodium chloride. Distillation in vacuo to 80° C. with full vacuum yielded a concentrate of 1-(3,4-dichlorophenyl)-1,2-cyclopropane-dicarboxylic acid, which was used “as is” for the next step, cyclization to the imide. A quantitative yield from the diester was assumed for calculation purposes.
Workup
- temperature(under reflux)
- temperaturemaintained at 70-75° C. for 1.5 hours
- distillationMethanol was slowly distilled off in vacuo to 70° C.
- customto give a heavy suspension, which
- customThe free dicarboxylic acid was precipitated with 31 kg of 32% hydrochloric acid
- extractionextracted with 100 kg ethyl acetate
- customThe lower aqueous phase was separated
- washwashed with 20 kg ethyl acetate
- washThe combined organic phases were washed with 50 L water
- distillationDistillation in vacuo to 80° C. with full vacuum
- customyielded
- concentrationa concentrate of 1-(3,4-dichlorophenyl)-1,2-cyclopropane-dicarboxylic acid, which
Sources & evidence
- ORD record
- ord-e08dba4b635b47479eeb1261fbf644cb
- Source dataset
- uspto-grants-2014_07
- Patent number
- US08765801B2
Reaction notes
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