Hydrochloric Acid → 1-tert-Butyl 18-(2,5-dioxopyrrolidin-1-yl) octadecanedioate

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Reaction Steps

Octadecanedioic acid mono-tert-butyl ester (4.2 g, 0.011 mol) was dissolved in THF (20 mL), TSTU (4 g, 0.013 mol) in acetonitrile (20 mL) was added and pH of the solution was adjusted to 8 with dropwise addition of DIPEA. The mixture was stirred at RT for 4 h, then acidified with HCl (2M) to pH 3 and evaporated in vacuo. The residual oil was subsequently partitioned between ethyl acetate and HCl (0.1 M). The organic layer was dried (MgSO4), filtered and evaporated to dryness in vacuo. This afforded 5.2 g of octadecanedioic acid tert-butyl ester 2,5-dioxopyrrolidin-1-yl ester as an oil, which could be used in the next step without further purification. LC-MS (electrospray): m/z=468 (M+1) and 412 (M+1-tBu).

Provenance & Evidence