Salicylic Acid → HCID 178510267, compound

HRID 1006709Notes

Reaction equation

[CH2:1]1[CH2:6][CH2:5][C:4]([CH2:11][NH2:12])([CH2:7][C:8]([OH:10])=[O:9])[CH2:3][CH2:2]1.[C:13]([OH:22])(=[O:21])[C:14]1[C:15](=[CH:17][CH:18]=[CH:19][CH:20]=1)[OH:16]>O>[CH2:1]1[CH2:2][CH2:3][C:4]([CH2:11][NH2:12])([CH2:7][C:8]([OH:10])=[O:9])[CH2:5][CH2:6]1.[C:13]([O-:22])(=[O:21])[C:14]1[C:15](=[CH:17][CH:18]=[CH:19][CH:20]=1)[OH:16]

Participants

Conditions

Temperature: 40 °C

Procedure

A solution of 20 kg of gabapentin in 140 liters of water is heated at 40° C. and added with 16.1 kg of salicylic acid. The suspension is stirred for 6 hours at 40° C., then cooled to 20° C., centrifuged and dried under vacuum at approx. 50° C. 34.5 kg (95.5% on theoretical) of 99.65% gabapentin salicylate are obtained, melting point 116° C. The elemental analysis (found C, 62.28%; H, 7.53%; N, 4.44%; calculated C, 62.12%; H, 7.49%; N, 4.53%) confirms the nature of the salt, which is suspended in 130 liters of absolute ethanol at 20° C., added with 15.9 kg of N-ethyl-diisopropylamine, then stirred at 20° C. for four hours, cooled to 8-10° C. and centrifuged, washing in centrifuge with approx. 20 liters of absolute ethanol. Drying affords 15.4 kg of gabapentin (86.68% yield), which can be further purified by suspension in 400 liters of ethanol containing 10% by weight of water and heating for some minutes, under stirring, at approx. 40° C. After standing at room temperature for four-five hours, the mixture is cooled to 0° C. and after, a further 4-5 hours at this temperature, is centrifuged and dried. The resulting pure gabapentin (87% yield) has content in salicylic acid lower than 100 ppm and in lactam lower than 0.1%.

Workup

temperaturecooled to 20° C.
customdried under vacuum at approx. 50° C

Sources & evidence

ORD record: ord-0965c248f2f34fb293e4b784449e2a0b
Source dataset: uspto-grants-2004_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06790986B1

Reaction notes

Loading…