Acetaldehyde → cis-4-amino-5-chloro-N-(1-ethyl-3-methoxy-4-piperidinyl)-2-methoxybenzamide monohydrate

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Reaction Steps

To 1 part of a solution of 2 parts of thiophene in 40 parts of ethanol were added 12 parts of an acetaldehyde solution 10% in tetrahydrofuran, 6.3 parts of cis-4-amino-5-chloro-2-methoxy-N-(3-methoxy-4piperidinyl)benzamide and 120 parts of methanol. The whole was hydrogenated at normal pressure and at room temperature with 2 parts of platinum-on-charcoal catalyst 5%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was suspended in a mixture of 2,2'-oxybispropane and petroleumether. The product was filtered off and crystallized from acetonitrile. The product was filtered off and dried, yielding a first fraction of 2 parts of cis-4-amino-5-chloro-N-(1-ethyl-3-methoxy-4-piperidinyl)-2-methoxybenzamide monohydrate; mp. 130.2° C. The mother liquor was concentrated. A second fraction was filtered off, yielding 2.89 parts of cis-4-amino-5-chloro-N-(1-ethyl-3-methoxy-4-piperidinyl)-2-methoxybenzamide monohydrate; mp. 150.5° C. (compound 146).

Provenance & Evidence