A ‘cold synthesis’ of heroin and implications in heroin signature analysis: Utility of trifluoroacetic/acetic anhydride in the acetylation of morphine

Abstract

Treatment of morphine, at room temperature, with a mixture of trifluoroacetic anhydride (TFAA) and acetic acid (20–30 min) affords good yields of heroin. GC–MS and HPLC examination shows that heroin produced by this route to be extremely clean, but the product contains slightly less heroin than observed via the more traditional acetic anhydride (AA) route (76.1% versus 83.55%); and greater quantities of 3-MAM and 6-MAM (6.9% versus 0.75% and 7.13% versus 0.63%). The concentration ratios of the major alkaloid impurities were found to be both production method (TFAA and AA) as well as morphine extraction methodology dependant. Data contained herein describe the impact of this new production method on current intelligence efforts, largely by-passing existing heroin signature programs and the UNDCP's efforts to restrict access to key synthetic precursors. Given the methodology dependency we find that examination of the major alkaloid ratios is unsuitable for the development of a new heroin signature program. Further examination of the TFAA methodology allowed the identification of TFAA specific marker compounds, namely bis-trifluoroacetylmorphine ( 30), 3-trifluoroacetyl-6-acetylmorphine ( 31), 3-acetyl-6-trifluoroacetylmorphine ( 32) and trifluoroacetylcodeine ( 33). However, the hydrolytic lability of trifluroacetyl esters requires careful treatment of suspect samples, thus we propose a modification to existing HSP's in instances were the 6-MAM/WM ratio falls within the average minimum and maximum values of 6.17 and 17.32.