The reaction of beta-chloroethylamine (III) with ammonium thiocyanate (B) gives beta-aminoethylthiocyanate (IV), which is alkylated with alpha,beta-dichloroethylbenzene (V) in hot benzene yielding the secondary amine (VI). The cyclization of (VI) in hot aqueous NaOH affords racemic levamisole, which is finally resolved in its optical isomers through the d-10-camphorsulfonate or N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The reaction of beta-chloroethylamine (III) with ammonium thiocyanate (B) gives beta-aminoethylthiocyanate (IV), which is alkylated with alpha,beta-dichloroethylbenzene (V) in hot benzene yielding the secondary amine (VI). The cyclization of (VI) in hot aqueous NaOH affords racemic levamisole, which is finally resolved in its optical isomers through the d-10-camphorsulfonate or N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The reaction of phenacyl bromide (VII) with 2-aminothiazoline (VIII) in MeCN at 100 C gives 2-imino-3-phenacylthiazolidine (IX), which is reduced to the corresponding alcohol (X) with NaBH4 in methanol. Finally, this compound is cyclized with SOCl2 and refluxing acetic anhydride giving the racemic levamisole which is resolved resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt. Compound (X) can be acetylated under milder conditions than before giving the N-acetyl compound (XI), which is cyclized SOCl2 and refluxing acetic anhydride.

The inactive d-(+)-levamisole can be isomerized by reaction with a strong nonaqueous base such as potassium tert-butylate, sodium amide or sodium hydride with or without solvent (DMF, DMSO). The racemic mixture obtained is resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The reaction of beta-chloroethylamine (III) with ammonium thiocyanate (B) gives beta-aminoethylthiocyanate (IV), which is alkylated with alpha,beta-dichloroethylbenzene (V) in hot benzene yielding the secondary amine (VI). The cyclization of (VI) in hot aqueous NaOH affords racemic levamisole, which is finally resolved in its optical isomers through the d-10-camphorsulfonate or N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The reaction of phenacyl bromide (VII) with 2-aminothiazoline (VIII) in MeCN at 100 C gives 2-imino-3-phenacylthiazolidine (IX), which is reduced to the corresponding alcohol (X) with NaBH4 in methanol. Finally, this compound is cyclized with SOCl2 and refluxing acetic anhydride giving the racemic levamisole which is resolved resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt. Compound (X) can be acetylated under milder conditions than before giving the N-acetyl compound (XI), which is cyclized SOCl2 and refluxing acetic anhydride.

The inactive d-(+)-levamisole can be isomerized by reaction with a strong nonaqueous base such as potassium tert-butylate, sodium amide or sodium hydride with or without solvent (DMF, DMSO). The racemic mixture obtained is resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The reaction of phenacyl bromide (VII) with 2-aminothiazoline (VIII) in MeCN at 100 C gives 2-imino-3-phenacylthiazolidine (IX), which is reduced to the corresponding alcohol (X) with NaBH4 in methanol. Finally, this compound is cyclized with SOCl2 and refluxing acetic anhydride giving the racemic levamisole which is resolved resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt. Compound (X) can be acetylated under milder conditions than before giving the N-acetyl compound (XI), which is cyclized SOCl2 and refluxing acetic anhydride.

The inactive d-(+)-levamisole can be isomerized by reaction with a strong nonaqueous base such as potassium tert-butylate, sodium amide or sodium hydride with or without solvent (DMF, DMSO). The racemic mixture obtained is resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The cyclization of (S)-(+)-phenylethylenediamine (I) with CS2 in alkaline water gives (S)-(+)-4-phenyl-2-mercaptoimidazolidine (II), which is then cyclized again with 1,2-dibromoethane (A) in alkaline isopropanol-water.

The cyclization of (S)-(+)-phenylethylenediamine (I) with CS2 in alkaline water gives (S)-(+)-4-phenyl-2-mercaptoimidazolidine (II), which is then cyclized again with 1,2-dibromoethane (A) in alkaline isopropanol-water.

The reaction of beta-chloroethylamine (III) with ammonium thiocyanate (B) gives beta-aminoethylthiocyanate (IV), which is alkylated with alpha,beta-dichloroethylbenzene (V) in hot benzene yielding the secondary amine (VI). The cyclization of (VI) in hot aqueous NaOH affords racemic levamisole, which is finally resolved in its optical isomers through the d-10-camphorsulfonate or N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.

The reaction of phenacyl bromide (VII) with 2-aminothiazoline (VIII) in MeCN at 100 C gives 2-imino-3-phenacylthiazolidine (IX), which is reduced to the corresponding alcohol (X) with NaBH4 in methanol. Finally, this compound is cyclized with SOCl2 and refluxing acetic anhydride giving the racemic levamisole which is resolved resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt. Compound (X) can be acetylated under milder conditions than before giving the N-acetyl compound (XI), which is cyclized SOCl2 and refluxing acetic anhydride.

The inactive d-(+)-levamisole can be isomerized by reaction with a strong nonaqueous base such as potassium tert-butylate, sodium amide or sodium hydride with or without solvent (DMF, DMSO). The racemic mixture obtained is resolved in its optical isomers through the d-10-camphorsulfonate, N-benzene (or p-toluene)sulfonyl-L-(+)-glutamic salt.