Salicylic Acid → HCID 178510267, compound

Participants

Reaction Conditions

Reaction Steps

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%.

Provenance & Evidence