Patent ID: 8153806

Claim:
A method of preparing R(+)-4-amino-thalidomide comprising: (a) contacting 3-nitrophthalic anhydride with R(+)-3-amino-glutarimide hydrobromide in the presence of acetic acid at a temperature of about 70° C. to about 80° C. for about 18 to about 24 hours to form R(+)-4-nitro-thalidomide; and (b) reducing the R(+)-4-nitro-thalidomide by hydrogenation to form R(+)-4-amino-thalidomide, wherein R(+)-(3-benzyloxycarbonylamino)-glutarimide is reacted with a mixture of hydrogen bromide and acetic acid to form the R(+)-3-amino-glutarimide hydrobromide.