Process for the preparation of chlorothiazole derivatives
AssigneeTakeda Chemical Industries, Ltd.
InventorsHideki Uneme, Noriko Higuchi, Isao Minamida
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Abstract
Novel processes for preparing 2-chlorothiazoles, useful as an intermediate for insecticides, from allyl isothiocyanate derivatives having the formula [II]: ##STR1## wherein X represents a leaving group, are simple and convenient reaction procedures under mild conditions without need of a large excess of a chlorinating agent. Further, processes for preparing 5-(aminomethyl)-2-chlorothiazole or salts thereof from the compound [II] achieve higher yields by simple, convenient and inexpensive procedures.
Claims11
A process for preparing 2-chloro-5-(chloromethyl)thiazole represented by ##STR22## which comprises reacting an allyl isothiocyanate derivative represented by the formula ##STR23## wherein X represents a leaving group selected from the group consisting of halogen;
- C.sub.1-4 alkylsulfonyloxy unsubstituted or substituted by 1 to 3 halogen atoms which may be the same or different;
- C.sub.6-10 arylsulfonyloxy unsubstituted or substituted by 1 to 4 substituents, which may be the same or different, selected from the group consisting of lower alkyl and halogen atoms;
- and C.sub.1-6 acyloxy unsubstituted or substituted by 1 to 3 halogen atoms which may be the same or different;
- with a chlorinating agent.
A process for preparing 5-(aminomethyl)-2-chlorothiazole ##STR24## or salts thereof which comprises reacting an allyl isothiocyanate derivative represented by the formula ##STR25## wherein X represents a leaving group with a chlorinating agent to produce 2-chloro-5-(chloromethyl)thiazole represented by ##STR26## and then reacting the resulting compound with an aminating agent.
Dependencies are inferred from the claim text.