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US 4,175,204 AGranted
Method of preparing E-4-acetoxy-2-methyl-2-butenal
OwnerJames H. Bablerinventor
Life of this patent
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Abstract
E-4-acetoxy-2-methyl-2-butenal is prepared by: (1) preparation of an intermediate allylic halide from isoprene; and (2) reaction of the allylic halide with dimethyl sulfoxide in the presence of a non-nucleophilic base to form the desired product.
Claims10
A process for synthesis of E-4-acetoxy-2-methyl-2-butenal comprising the following steps in sequence:
- (a) forming a reaction mixture of 4-halo-3-methyl-2-buten-1-ol acetate, dimethyl sulfoxide, and a non-nucleophilic base;
- (b) isolating E-4-acetoxy-2-methyl-2-butenal as a reaction product from said reaction mixture.
A process for synthesis of E-4-acetoxy-2-methyl-2-butenal comprising the following steps in sequence:
- (a) forming a first reaction mixture of isoprene, acetic acid and a source of positive halogen;
- (b) isolating 4-halo-3-methyl-2-buten-1-ol acetate as a reaction product from said first reaction mixture;
- and
- (c) forming a second reaction mixture of 4-halo-3-methyl-2-buten-1-ol acetate, dimethyl sulfoxide, and a non-nucleophilic base;
- (d) isolating E-4-acetoxy-2-methyl-2-butenal as a reaction product from said second reaction mixture.
2 more elements
A process for synthesis of E-4-acetoxy-2-methyl-2-butenal comprising the following steps in sequence:
- (a) forming a first reaction mixture comprising an aqueous solution of isoprene, a hypochlorite, and a stream of gaseous carbon dioxide;
- (b) isolating 1-chloro-2-methyl-3-buten-2-ol as a reaction product from said first reaction mixture;
- and
- (c) forming a second reaction mixture of 1-chloro-2-methyl-3-buten-2-ol, acetic acid, acetic anhydride and a strong acid catalyst;
- (d) isolating 4-chloro-3-methyl-2-buten-1-ol acetate as a reaction product from said second reaction mixture;
- and
- (e) forming a third reaction mixture of 4-chloro-3-methyl-2-buten-1-ol acetate, dimethyl sulfoxide, and a non-nucleophilic base selected from the group consisting of dibasic sodium phosphate and dibasic potassium phosphate;
- (f) isolating E-4-acetoxy-2-methyl-2-butenal as a reaction product from said third reaction mixture.
5 more elements
Dependencies are inferred from the claim text.