[EN] PROCESSES FOR PRODUCING 3-(METHYLTHIO) THIOPHENE<br/>[FR] PROCÉDÉS DE PRODUCTION DE 3-(MÉTHYLTHIO)THIOPHÈNE
申请人:ALBEMARLE CORP
公开号:WO2011041126A1
公开(公告)日:2011-04-07
Processes are provided for producing 3-(methylthio) thiophene by (i) combining at least an alkyl lithium, one or more alkanes and an ether to form a first combination, (ii) at a temperature of about -30°C to about -25°C and over a time period of at least about 30 minutes, adding 3-bromothiophene diluted in an ether to the first combination to form a second combination, (iii) at a temperature of about -25°C to about -20°C combining at least the second combination and dimethyl disulfide, and (iv) yielding at least the 3-(methylthio) thiophene.
Analgesic compounds are of the general formula (I):
in which, R¹ and R² each represents hydrogen or C₁-C₆ alkyl, or R¹ and R² together with the nitrogen atom to which they are attached form a heterocycle; E represents methylene, sulphur, oxygen or imino group optionally substituted with C₁-C₆ alkyl or aralkyl; ring A is aryl or heteroaryl ring, optionally substituted; R³ is hydrogen or C₁-C₆ alkyl and R⁴ is hydrogen or R³ and R⁴ together represent a group of formula (IV):
-(CRaRa)m-C(=Y)- (IV)
(wherein Ra and Ra is C₁-C₆ alkyl or hydrogen, up to a maximum of 3 alkyl groups, m is 1, 2, or 3, and Y is two hydrogens or oxygen); provided that when E represents a methylene group, then R³ is a C₁-C₆ alkyl group or R³ and R⁴ together represent a group of the formula (IV).