5-Aminosalicylic acid synthesis
- Product Name:5-Aminosalicylic acid
- CAS Number:89-57-6
- Molecular formula:C7H7NO3
- Molecular Weight:153.14
96-97-9
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$14.14/1gm:
89-57-6
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Yield:89-57-6 91.6%
Reaction Conditions:
Stage #1: 5-nitrosalicylic acid at 95 - 98; pH=2;
Stage #2: with sodium hydroxide at 85 - 95; pH=11.5 - 12; for 2.5 h;Product distribution / selectivity;
Steps:
5
Fourth recycle: In the same set up as described above, 250 ml reaction medium generated in third cycle, heated to 95°C. Charge 28.125 g G-CAT start up with continuous stirring at 95°C. First lot of 1.34 g G-CAT and first lot of 3.571 g Nitro and 8.9 ml reaction medium was charged to the reaction mass in 20 min. The reaction mass was maintained for 5-10 min at 95°C. Remaining G-CAT & Nitro was charged in four equal lots in similar manner as followed for first lot. Reaction mass was maintained at 98°C for 30 min. Then 75 ml of reaction medium was added and reaction was maintained at 98°C for 30 min. 5.0 g R-Cat was charged during 30 min. Then add 12.5 ml of 50% NaOH in 1 hr at 85-90°C in 1 hr to adjust pH of reaction mass to 11.5 to 12 and maintain for 30 minutes. Then settle the batch for 45 minutes and decant it. Add 75 ml reaction medium and maintain the mass in alkaline condition at 95°C for 30 minutes and filter the batch. The spent catalyst was washed with the mixture of 27.5 ml of reaction medium and 10 ml of fresh alkaline water. Collect decant, filtrate and wash layers together and to this add 1.25 g hydrose and 26 ml of 20% H2SO4 at 50°C in 3 hrs. Cool the reaction mass to ambient temperature and maintained for 2 hours; crystalline material was filtered, to get on drying 22.9 g of bluish Violet powder with purity 97.65%. Total filtrate i.e. reaction medium and washings was collected & recycled in subsequent batches.
References:
WO2011/48535,2011,A1 Location in patent:Page/Page column 46; 49
119-30-2
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89-57-6
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124-38-9
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$214.00/14L
103-90-2
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$9.00/1g
89-57-6
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$5.00/50mg
89-55-4
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$9.00/5g
89-57-6
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$5.00/50mg
321-14-2
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$15.00/25g
89-57-6
764 suppliers
$5.00/50mg