Reaktion #725336

Reaktionsgleichung

2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate

chlorine

→

5-chloro-2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate

Ausbeute 88.9%

Lösungsmittel

carbon tetrachloride

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas gradually fed at a temperature of from 10° to 15° C.
2. 2
   FiltrationThe precipitated crystals were collected by filtration
3. 3
   Waschenwashed with hexane

Vorschrift

To a solution of 2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate (33.2 g, 0.15 mol) in 150 ml of chloroform and 300 ml of carbon tetrachloride, chlorine (10.7 g, 0.15 mol) was gradually fed at a temperature of from 10° to 15° C. under stirring. The precipitated crystals were collected by filtration and washed with hexane, whereby 34.1 g of 5-chloro-2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate was obtained. The melting of this product was 167°-169° C. The structure was confirmed by 1H-NMR spectrum. Then, the product was added to 100 ml of a 10% aqueous sodium hydroxide-methanol solution and heated at 80° C. for 3 hours. The reaction solution was neutralized with hydrochloric acid and extracted with ether. The ether layer was washed with water, dried over anhydrous sodium sulfate and concentrated, whereby 23.0 g of 5-chloro-2,3-dihydro-2,2-dimethyl-7-benzofuranol was obtained. The melting point of this product was 65.5°-66.5° C. The phenol thus obtained, was reacted with O-ethyl-S-n-propyldithiophosphoryl chloride in the same manner as in Example 1, whereby the compound (No. 18) identified in Table 1 was obtained.

Quelle