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[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.[CH3:8][C:9]([CH3:11])=[CH2:10].C(C1C=C(O)C(=CC=1)O)(C)(C)C>C1(C)C=CC=CC=1>[C:4]1(=[O:5])[O:6][C:1](=[O:7])[CH:2]=[CH:3]1.[CH2:10]([CH:3]1[C:4](=[O:5])[O:6][C:1](=[O:7])[CH2:2]1)[C:9](=[CH2:8])[CH3:11]참가 물질
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- 온도
- 60 °C
실험 절차
This method describes an improved method for the synthesis of D,L-2-isobutyl-3-(methoxycarbonyl)-propionic acid (3). Maleic anhydride (750 g, 7.65 moles) was dissolved in hot toluene (500 mL), filtered, and allowed to cool thus producing a finely divided crystalline precipitate. The resulting mixture was further cooled in a refrigerator. 2-Methylpropene was condensed into cold toluene (1 L). The cold maleic anhydride suspension was transferred, with the aid of additional toluene (300 mL), to the glass liner of a Parr 2 gallon stirred autoclave. The 2-methylpropene solution was then added followed by 4-tert-butyl catechol (2 g). The autoclave was sealed and heated, with stirring, to 170° C. over 45 minutes and maintained at that temperature for an additional 9.5 hours. The reaction was then allowed to cool to 60° C. over 7 hours after which, the autoclave was vented. After an additional 1.5 hours, the internal temperature had reached 45° C. and the autoclave was opened. The solvent was removed and the residue was distilled under aspirator pressure through a 10 inch vacuum jacketed Vigreux column fitted with a partial take off head to give unreacted maleic anhydride (139.4 g, 18.6% yield) and β-methallylsuccinic anhydride (765.3 g, 79.8% yield).
후처리
- filtrationfiltered
- temperatureto cool thus
- customproducing a finely divided crystalline precipitate
- temperatureThe resulting mixture was further cooled in a refrigerator
- customThe autoclave was sealed
- temperatureheated
- stirringwith stirring, to 170° C. over 45 minutes
- temperaturemaintained at that temperature for an additional 9.5 hours
- customhad reached 45° C.
- customThe solvent was removed
- distillationthe residue was distilled under aspirator pressure through a 10 inch vacuum
- customfitted with a partial take off head
출처 및 근거
- ORD 기록
- ord-2a8906d616e042a88d447ef54acf0a7b
- 출처 데이터셋
- uspto-grants-1999_04
- 특허 번호
- US05892112
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