Triethylamine → HCID 507307, compound

Thionyl chloride (6.5 g, 0.055 mole) was added to a stirred mixture of 5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxylic acid (8.0 g, 0.050 mole) and methylene chloride (50 ml). The mixture was warmed to 35°-40° C. for hours and the resulting dark solution evaporated under reduced pressure. The solid residue, crude 5,6-dihydro-2-methyl-1,4-oxathiin-3-carbonyl chloride, was dissolved in methylene chloride (50 ml). On the following day, the solution was treated dropwise at 5°-20° C. over 2 hours with a solution of ethyl 3-aminobenzoate (8.2 g, 0.050 mole) and triethylamine (5.5 g, 0.054 mole) in methylene chloride (50 ml). The reaction mixture was stirred at room temperature for a further 5 hours and worked up by washing in sequence with water (50 ml), dilute hydrochloric acid (3.5%, 50 ml), water (50 ml), dilute sodium hydroxide (2%, 25 ml) and water (50 ml). Evaporation of the solvent left an oil, which slowly solidified. Recrystallization from ethanol 75 ml gave yellow-tan crystals, m.p. 100° -102° C. (11.2 g, 73% yield).

1. temperatureThe mixture was warmed to 35°-40° C. for hours
2. customthe resulting dark solution evaporated under reduced pressure
3. dissolutionThe solid residue, crude 5,6-dihydro-2-methyl-1,4-oxathiin-3-carbonyl chloride, was dissolved in methylene chloride (50 ml)
4. washby washing in sequence with water (50 ml), dilute hydrochloric acid (3.5%, 50 ml), water (50 ml), dilute sodium hydroxide (2%, 25 ml) and water (50 ml)
5. customEvaporation of the solvent
6. waitleft an oil, which
7. customRecrystallization from ethanol 75 ml
8. customgave yellow-tan crystals, m.p. 100° -102° C. (11.2 g, 73% yield)

ORD record

ord-7f7d693bea1e4d1d8a24409909fbe53a

Source dataset

uspto-grants-1993_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05268389