D(+)-Malic acid synthesis
- Product Name:D(+)-Malic acid
- CAS Number:636-61-3
- Molecular formula:C4H6O5
- Molecular Weight:134.09
56-84-8
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636-61-3
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$6.00/5g
4198-33-8
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6915-18-0
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Yield:4198-33-8 86% ，636-61-3 0.1% ，6915-18-0 0.1%
Reaction Conditions:
with hydrogenchloride;sodium nitrite in water at -15 - 0; for 8 h;
Steps:
2 Example 2; Preparation of chlorosuccinic acid; "Reaction B"
To a vigorously stirred mixture of mother waters and washing waters (approximately 650 ml) from the previous reaction are added 200 g (1.50 mol) of L-aspartic acid, 360 ml (428.4 g) of 37% HCl (158.51 g of HCl, 4.35 mol) and 100 ml of demineralised water; 184 g (2.66 mol) of solid sodium nitrite are then added in approximately 2 hours at a temperature of ?5 C. under nitrogen blanket. Stirring is continued at the same temperature for 2.5 hours, the temperature is raised to +0 C. in the space of approximately 1 hour, the mixture is left at this temperature for another period of 1 hour, and the temperature then lowered to ?15 C. After 1.5 hours at this temperature, the mixture is vacuum filtered on Buchner filters and left to drain under vacuum pump aspiration for approximately 0.5 hours. The solid is then washed with 80 ml of water at 0 C. and left on a vacuum filter for another 1.5 hours. [00082] The crude product is vacuum dried in an oven at 40 C. It presents approximately 15-20% sodium chloride contamination. [00083] The molar percentages of the impurities present, calculated on the basis of the NMR spectrum, are the following: [TABLE-US-00002] fumaric acid 0.1-0.2% w/w malic acid 0.1-0.4% w/w aspartic acid 0.1-0.2% w/w [00084] The yield of S-(?)-chlorosuccinic acid, calculated 100% pure, is 86-87%. [00085] The pure product, obtained by means of a further crystallisation of a sample of the crude product with water, has a melting point of 180-182 C. [00086] The overall yield of reactions A+B is 83-84%.
References:
Sigma-Tau Industrie Farmaceutiche Riunite S.p.A. US6677476, 2004, B1 Location in patent:Page column 9
328-42-7
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636-61-3
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617-48-1
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636-61-3
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16045-92-4
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636-61-3
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