1-Hydroxybenzotriazole → HCID 10791723, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.149 g) in dichloromethane (3 ml) was added to a solution of (R)-(−)-1,2,4,5-tetrahydro-7,8-dimethoxy-5-oxo-3-benzothiepin-2-carboxylic acid (0.183 g) and diethyl 4-aminobenzylphosphonate (0.158 g) in N,N-dimethylformamide (DMF) (3 ml) at 0° C., followed by the addition of 1-hydroxybenzotriazole (HOBt) (0.109 g). This mixture was stirred at 0° C. for 1 hour and at room temperature for 15 hours, after which it was poured into water and extracted with ethyl acetate. The ethyl acetate layer was washed with water and dried (MgSO4), after which the solvent was distilled off; the residue was treated with ethanol-isopropyl ether and the solid was removed by filtration. The filtrate was concentrated and the residual oil was subjected to silica gel column chromatography. From the fraction eluted with ethyl acetate-chloroform-methanol (15:15:1, v/v), (2R)-(−)-N-[4-(diethoxyphosphorylmethyl)phenyl]-1,2,4,5-tetrahydro-7,8-dimethoxy-5-oxo-3-benzothiepin-2-carboxamide (0.136 g, 41%) was obtained. Colorless amorphous solid. Melting point 96-98° C. Optical rotation [α]D (23° C.) −155.0° (c=0.50, CHCl3).

Provenance & Evidence