4-Thiazoleethanol, 2-(4-chlorophenyl)- → 6,7-dihydro-4-ethyl-2-(4-chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetic acid

HRID 258579Notes

Reaction equation

HRID 258579 reaction equation
C1(C2SC=C(CCO)N=2)C=CC=CC=1.ClC1C=CC(C2SC=C(CCO)N=2)=CC=1.[CH2:30]([C:32]1([CH2:48][C:49]([O:51]CC)=[O:50])[C:40]2[S:39][C:38]([C:41]3[CH:46]=[CH:45][C:44]([Cl:47])=[CH:43][CH:42]=3)=[N:37][C:36]=2[CH2:35][CH2:34][O:33]1)[CH3:31]>>[CH2:30]([C:32]1([CH2:48][C:49]([OH:51])=[O:50])[C:40]2[S:39][C:38]([C:41]3[CH:46]=[CH:45][C:44]([Cl:47])=[CH:43][CH:42]=3)=[N:37][C:36]=2[CH2:35][CH2:34][O:33]1)[CH3:31]

Participants

4

Reactant 3

HCID 6105314-Thiazoleethanol, 2-(4-chlorophenyl)-HCID 106083152-Phenyl-4-(beta-hydroxyethyl)thiazoleHCID 53858402ethyl 6,7-dihydro-4-ethyl-2-(4chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetate

Product 1

HCID 124290086,7-dihydro-4-ethyl-2-(4-chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetic acid

Procedure

In the same manner but replacing 2-phenyl-4-(β-hydroxyethyl)thiazole with an equivalent amount of 2-(4-chlorophenyl)-4-(β-hydroxyethyl)thiazole the intermediate ester, ethyl 6,7-dihydro-4-ethyl-2-(4chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetate (IV, R1 = Cl, R2 = CH2CH3, A= COOCH2CH3 and n= 1is obtained. Alkaline hydrolysis of the latter ester gives 6,7-dihydro-4-ethyl-2-(4-chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetic acid (I; R1 = Cl, R2 = CH2CH3, R3 = COOH and n= 1), mp 190°-191° C., after crystallization from methanol. The ether extract obtained from the alkaline aqueous solution is purified to give the by-products 6,7-dihydro-4-ethyl-4-methyl-2-(4-chlorophenyl)-4H-pyrano[4,3-d]thiazole hydrochloride, mp 153°-154° C., after trituration with ether containing hydrogen chloride.

Workup

  1. customA= COOCH2CH3 and n= 1is obtained

Sources & evidence

ORD record
ord-5fe5f9ee00f44dfba28b5a7dc8091ce8
Source dataset
uspto-grants-1977_07
Patent number
US04033977

Reaction notes

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