Silicon Containing Carbamates with Muscle Relaxant Activity

1 Silicon Containing Carbamates with Muscle Relaxant Activity 

An extensive study of Fessenden69 is concerned with biological effects of twelve pairs of carbamates (64a/64b-75a/75b) (Table 9), each pair differing by only one atom (silicon in place of carbon). The most prominent of this series is the centrally acting muscle relaxant and tranquilizer meprobamate (66a). 

The carbamates were tested (intraperitoneal application) using mice for acute toxicity. For sublethal activity the rotating rod test and the extension of hexobar-bital sleeping time was used. 

Each pair of compounds tested, with one exception, was essentially equivalent in their acute toxicities (compare Table 10). 73b (450 mg/kg) and 73a (32 mg/kg) differed by a factor of 10 in toxicity. 

Compound LD5oa (mg/kg] EDsob (mg/kg I Compound LD50a [mg/kg] EDsob (mg/kg] 

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