Hydrochloric Acid → (R)-5,5-Dimethyl-thiazolidine-4-carboxylic acid allylamide hydrochloride

Participants

Reaction Conditions

Reaction Steps

A solution of (R)-5,5-Dimethyl-thiazolidine-3,4-dicarboxylic acid 3-tert-butyl ester (105 kg, 402 mol) and ethyl acetate (690 L) was treated with diphenylchlorophosphate (113 kg, 422 mol) and was then cooled to 0° C. NEt3 (85.5 kg, 844 mol) was added while maintaining the temperature at 5° C., and the mixture was then held at this temperature for 2 h. The mixture was cooled to 0° C., and allylamine (24.1 kg, 422 mol) was then added while maintaining the temperature at 5° C. The mixture was warmed to 20° C. and was then quenched with 10 wt. % aqueous HCl (310 L). After separation ofthe layers, the organic fraction was washed with 8.6 wt. % aqueous Na2CO3 (710 L). After separation of the layers, the aqueous fraction was extracted with ethyl acetate (315 L). The combined ethyl acetate extracts containing AG-074278 were dried by azeotropic distillation at one atmosphere, while maintaining a minimum pot volume of approximately 315 L. The resulting suspension of (R)-4-Allylcarbamoyl-5,5-dimethyl-thiazolidine-3-carboxylic acid tert-butyl ester was cooled to 5° C. A 13 wt. % solution of anhydrous HCl (36.8 kg, 1008 mol) in ethyl acetate (263 L) was cooled to 5° C. and was then added to the (R)-4-Allylcarbamoyl-5,5-dimethyl-thiazolidine-3-carboxylic acid tert-butyl ester suspension while maintaining the temperature at 15° C. The resulting suspension was held at 20° C. for 19 h, and was then cooled and held at 5° C. for 2 h. The suspension was then filtered, using cold ethyl acetate for rinsing. The wet cake was dried under vacuum at 45° C. to give 90.5 kg (95.2%) of (R)-5,5-Dimethyl-thiazolidine-4-carboxylic acid allylamide hydrochloride as a white solid: 1H NMR (300 MHz, DMSO-d6) δ 8.94 (app t, J=5.5 Hz, 1H), 5.82 (ddt, J=10.4, 17.2, 5.2 Hz, 1H), 5.19–5.25 (m, 1H), 5.10–5.14(m, 1H),4.38(ABq, JAB=9.8Hz, Δν=14.5Hz, 2H),4.08(s, 1H), 3.72–3.91 (m, 2H), 1.58 (s, 3H), 1.32 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ 161.7, 132.2, 114.0, 67.9, 51.4, 43.5, 39.3, 25.3, 24.3; MS (CI) m/z 201.1070 (201.1062 calcd for C9H17N2OS, M+H+); elemental analysis calcd for C9H17ClN2OS: C, 45.65; H, 7.24; N, 11.83; Cl, 14.97; found: C, 45.41; H, 7.33; N, 11.69; Cl, 15.22.

Provenance & Evidence