Formaldehyde → (+/-) 5-(2-Thienyl)-3-(methoxycarbonyl-o-chlorobenzyl)-1,3-oxazoline

HRID 2299274Notes

Reaction equation

[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH:6]([OH:21])[CH2:7][NH:8][CH:9]([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[Cl:20])[C:10]([O:12][CH3:13])=[O:11].[CH2:22]=O>C(O)C>[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]1[O:21][CH2:22][N:8]([CH:9]([C:10]([O:12][CH3:13])=[O:11])[C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=2[Cl:20])[CH:7]=1

Participants

Conditions

Temperature: 40 °C

Procedure

Methyl N-(2-(2-thienyl)-2-hydoxyethyl)-2-o-chlorophenylglycinate (21) (2.5 g, 7.6 mmol) was dissolved in ethanol and treated with 37% formaline (1.85 g, 22.8 mmol), then heated at 40° C. over the night under nitrogen. The ethanol is evaporated under vacuum and the residual water was removed by azeotropic distillation with toluene to provide 2.3 g of desired product as a mixture of diastereoisomers. 1H-NMR (CDCl3, ppm) 7.72 (1H, m), 7.43 (1H, m), 7.2-7.3 (2H, m), 7.15 (1H, m), 6.95 (2H, m), 5.35 (1H, q), 5.15 and 5.05 (2H, 2s), 4.55 (2H, q), 4.40 (2H, q), 3.75 and 3.70 (3H, 2s), 3.3-3.5 (1H, m), 2.9-3.1 (1H, m).

Workup

customThe ethanol is evaporated under vacuum
customthe residual water was removed by azeotropic distillation with toluene

Sources & evidence

ORD record: ord-421ab239e5e04a0787bba88f6f07f6be
Source dataset: uspto-grants-2002_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06495691B1

Reaction notes

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