SHA-68 is a drug which acts as a selective, non-peptide antagonist at the neuropeptide S receptor NPSR. In animal studies it reduced motor stereotypes, and blocks the stimulant action of neuropeptide S.
The synthesis of SHA-68 was shown in a patent (ref example 1, Ex 1, Ex 2, Ex 16).
The Grignard reaction between Methyl 2-piperazine carboxylate [2758-98-7] (1) and phenylmagnesium bromide [100-58-3] (2) occurs to give alpha,alpha-Diphenyl-2-piperazinemethanol [17532-20-6] (3). {This compound is called Azapipradrol}. Protection of the sterically more accessible piperazine nitrogen with Boc anhydride occurs to give PC23122074 (4). Treatment with ethyl chloroformate [541-41-3] (5) gives the cyclic urethane and hence, PC68420957 (6). Deprotection of the Boc group in the presence of trifluoroacetic acid gave 1,1-Diphenyltetrahydro-1H-oxazolo[3,4-a]pyrazin-3(5H)-one [847555-93-5] [847556-28-9] (7). Lastly, treatment with 4-fluorophenyl isocyanate [1195-45-5] (8) gave the substituted urea, thus completing the synthesis of SHA-68 (9).
SAR reveals similarity to RTI-118 and contains the same precursor.